Bugfix: Ensure that a URL is always set.

This patch touches #358.

Indeed, before this patch, the special rules may have been
unstable when testing domains (not URL).
This patch fixes the issue by ensuring that our http_status_code
lookup is always done against a URL - if the testeted subject is
not an http(s) URL.

Contributors:
  * @spirillen

PyFunceble/checker/availability/base.py

@@ -928,6 +928,10 @@ def try_to_query_status_from_http_status_code(
             self.http_status_code_query_tool.set_subject(
                 f"http://{self.idna_subject}:80"
             )
+        elif not self.idna_subject.startswith("http"):
+            self.http_status_code_query_tool.set_subject(
+                f"http://{self.idna_subject}:80"
+            )
 
         lookup_result = self.http_status_code_query_tool.get_status_code()