Ignore {error,bad_module} in ejabberd_loglevel:set/1.

Two errors reported:

 - no match of right hand value {error,bad_module} in ejabberd_loglevel:set/1 line 71     <<<== This is where lager_console_backend log level is set.
 
- @lager_handler_watcher:98 Lager fatally failed to install handler lager_console_backend into lager_event, NOT retrying: old_shell

 

 
Here is the link to the log files generated (erl CRASH and ejabberd.log)
http://pastie.org/private/xgwkxlh6jj2sfc9tknigew