handle invalid log level strings. (FSCORE-69)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@6604 d0543943-73ff-0310-b7d9-9358b9ac24b2

conf/autoload_configs/switch.conf.xml

@@ -4,7 +4,7 @@
     <param name="max-sessions" value="1000"/>
     <!--Most channels to create per second -->
     <param name="sessions-per-second" value="30"/>
-    <!--Default Global Log Level -->
+    <!-- Default Global Log Level - value is one of debug,info,notice,warning,err,crit,alert -->
     <param name="loglevel" value="debug"/>
     <!--Try to catch any crashes that can be recoverable (in the context of a call)-->
     <param name="crash-protection" value="false"/>