don't fail on CLI plugins without docstrings

Related: https://pagure.io/koji/issue/644

docs/source/writing_a_plugin.rst

@@ -206,6 +206,7 @@ Most simple command would look like this:
 
     @export_cli
     def anon_handle_echo(options, session, args):
+        "[info] Print arguments"
         usage = _("usage: %prog echo <message>")
         parser = OptionParser(usage=usage)
         (opts, args) = parser.parse_args(args)