plugin XEP-0277: don't wrap DataError in failure.Failure in parseCommentUrl as it is not catched correctly:

`failure.Failure` is subclass of `BaseException` but not of `Exception`, as a result
`except Exception` doesn't catch it correctly. This is fixed by not wrapping `DataError`
in `failure.Failure` anymore.

sat/plugins/plugin_xep_0277.py

@@ -1005,7 +1005,7 @@ class XEP_0277(object):
         node = parsed_queries.get("node", [""])[0]
 
         if not node:
-            raise failure.Failure(exceptions.DataError("Invalid comments link"))
+            raise exceptions.DataError("Invalid comments link")
 
         return (service, node)