if isn't agreed cqlsh won't be returning failure

So far if a query is executed during schema changes that takes
more then 5sec to be resolved, cqlsh would print a warning
and change the return status to failure.

if it's just a warning, we shouldn't be failure the command.
especily since after this warning we are waiting without a timeout
for schema to be resolved.

Fixes: #34

bin/cqlsh.py

@@ -152,7 +152,7 @@ def find_zip(libprefix):
 from cqlshlib import cql3handling, pylexotron, sslhandling, cqlshhandling, authproviderhandling
 from cqlshlib.copyutil import ExportTask, ImportTask
 from cqlshlib.displaying import (ANSI_RESET, BLUE, COLUMN_NAME_COLORS, CYAN,
-                                 RED, WHITE, FormattedValue, colorme)
+                                 RED, YELLOW, WHITE, FormattedValue, colorme)
 from cqlshlib.formatting import (DEFAULT_DATE_FORMAT, DEFAULT_NANOTIME_FORMAT,
                                  DEFAULT_TIMESTAMP_FORMAT, CqlType, DateTimeFormat,
                                  format_by_type)
@@ -1110,8 +1110,8 @@ def perform_simple_statement(self, statement):
             try:
                 self.conn.refresh_schema_metadata(5)  # will throw exception if there is a schema mismatch
             except Exception:
-                self.printerr("Warning: schema version mismatch detected; check the schema versions of your "
-                              "nodes in system.local and system.peers.")
+                self.printwarn("Warning: schema version mismatch detected; check the schema versions of your "
+                               "nodes in system.local and system.peers.")
                 self.conn.refresh_schema_metadata(-1)
 
         if result is None:
@@ -2290,6 +2290,13 @@ def printerr(self, text, color=RED, newline=True, shownum=None):
             text = '%s:%d:%s' % (self.stdin.name, self.lineno, text)
         self.writeresult(text, color, newline=newline, out=sys.stderr)
 
+    def printwarn(self, text, color=YELLOW, newline=True, shownum=None):
+        if shownum is None:
+            shownum = self.show_line_nums
+        if shownum:
+            text = '%s:%d:%s' % (self.stdin.name, self.lineno, text)
+        self.writeresult(text, color, newline=newline, out=sys.stderr)
+
     def stop_coverage(self):
         if self.coverage and self.cov is not None:
             self.cov.stop()