existsPageForLanguage > loads TOC (table of contents) of nonexistent languages

[mcRoot]

If we are requesting a page belonging to a language not defined in a given package, it is useless to (try to) load the TOC for that language.
See sample error below:

java.nio.file.NoSuchFileException: /data/mn1/tomcat/./.docetdata/userguide_1495189343330/docs/fr/toc.html
        at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
        at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:214)
        at java.nio.file.Files.newByteChannel(Files.java:361)
        at java.nio.file.Files.newByteChannel(Files.java:407)
        at docet.DocetUtils.fastReadFile(DocetUtils.java:123)
        at docet.engine.DocetManager.loadTocForPackage(DocetManager.java:431)
        at docet.engine.DocetManager.existsPageForLanguage(DocetManager.java:1061)
        at magnews.backend.docet.DocetFileManager.existspageIdForPackageAndLanguage(DocetFileManager.java:197)
        at magnews.backend.framework.PageContext.existsCurrentDocumentationPageForLanguage(PageContext.java:2932)
        at sun.reflect.GeneratedMethodAccessor733.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at it.camuffo.CamuffoMethod.invoke(CamuffoMethod.java:125)
        at it.camuffo.scripting.MethodCallExpression.evaluate(MethodCallExpression.java:54)
        at it.camuffo.scripting.FieldAccessExpression.evaluate(FieldAccessExpression.java:45)
        at it.camuffo.scripting.ExpressionEvaluator.evaluate(ExpressionEvaluator.java:35)
        at it.camuffo.scripting.ExpressionEvaluator.evaluate(ExpressionEvaluator.java:31)
        at it.camuffo.CamuffoContext.evaluateExpression(CamuffoContext.java:232)
        at it.camuffo.tags.CFIfTag.evaluateCondition(CFIfTag.java:118)
        at it.camuffo.tags.CFIfTag.execute(CFIfTag.java:74)
        at it.camuffo.tags.CFIfTag.execute(CFIfTag.java:68)
        at it.camuffo.CamuffoEngine.executeTagNode(CamuffoEngine.java:182)
        at it.camuffo.CamuffoEngine.execute(CamuffoEngine.java:392)
        at it.camuffo.tags.CFIfTag.execute(CFIfTag.java:77)
        at it.camuffo.tags.CFIfTag.execute(CFIfTag.java:68)
        at it.camuffo.CamuffoEngine.executeTagNode(CamuffoEngine.java:182)
        at it.camuffo.CamuffoEngine.execute(CamuffoEngine.java:392)
        at it.camuffo.tags.CFOutputTag.execute(CFOutputTag.java:43)
        at it.camuffo.CamuffoEngine.executeTagNode(CamuffoEngine.java:182)
        at it.camuffo.CamuffoEngine.execute(CamuffoEngine.java:392)
        at it.camuffo.CamuffoEngine.execute(CamuffoEngine.java:386)
        at it.camuffo.CamuffoEngine.executeAsIntepreted(CamuffoEngine.java:162)
        at it.camuffo.CamuffoEngine.executeModule(CamuffoEngine.java:281)
        at it.camuffo.tags.DynamicModuleTag.execute(DynamicModuleTag.java:60)
        at it.camuffo.CamuffoEngine.executeTagNode(CamuffoEngine.java:182)
        at it.camuffo.CamuffoEngine.execute(CamuffoEngine.java:392)
        at it.camuffo.CamuffoEngine.execute(CamuffoEngine.java:386)
        at it.camuffo.CamuffoEngine.executeAsIntepreted(CamuffoEngine.java:162)
        at it.camuffo.CamuffoEngine.includeTemplate(CamuffoEngine.java:235)
        at it.camuffo.runtime.CamuffoInterpreterServlet.processRequest(CamuffoInterpreterServlet.java:115)
        at it.camuffo.runtime.CamuffoInterpreterServlet.doGet(CamuffoInterpreterServlet.java:272)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
        at sun.reflect.GeneratedMethodAccessor63.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:282)
        at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:279)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAsPrivileged(Subject.java:549)
        at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:314)
        at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:170)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:224)
        at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:46)
        at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:148)
        at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:144)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:143)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:726)
        at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:592)
        at org.apache.catalina.core.ApplicationDispatcher.access$100(ApplicationDispatcher.java:63)
        at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:112)
        at org.apache.catalina.core.ApplicationDispatcher$PrivilegedInclude.run(ApplicationDispatcher.java:100)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:517)
        at org.apache.jsp.tag.web.layoutInsert_tag.doTag(layoutInsert_tag.java:110)```