Correct reraising of exception

When an exception was caught and rethrown, it should
call 'raise' without any arguments because it shows
the place where an exception occured initially instead
of place where the exception re-raised

Change-Id: I3667715dc1bb4d8d56ad7a8c660c61fa676cdf9f

monasca_notification/plugins/jira_notifier.py

@@ -84,9 +84,9 @@ class JiraNotifier(AbstractNotifier):
             try:
                 with open(self._config.get("custom_formatter")) as f:
                     jira_fields_format = yaml.load(f)
-            except Exception as e:
+            except Exception:
                 self._log.exception("Unable to read custom_formatter file. Check file location")
-                raise e
+                raise
             # Remove the top element
             jira_fields_format = jira_fields_format["jira_format"]