Fix catching ParserError from arrow

pagure/api/user.py

@@ -289,7 +289,7 @@ def api_view_user_activity_date(username, date):
     try:
         date = arrow.get(date)
         date = date.strftime('%Y-%m-%d')
-    except arrow.ParserError as err:
+    except arrow.parser.ParserError as err:
         raise pagure.exceptions.APIError(
             400, error_code=APIERROR.ENOCODE, error=str(err))