[twitter] improve error handling

- handle accounts without 'rest_id'
- handle timelines with empty 'instructions'

gallery_dl/exception.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2015-2021 Mike Fährmann
+# Copyright 2015-2022 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -33,12 +33,12 @@ class GalleryDLException(Exception):
     msgfmt = None
     code = 1
 
-    def __init__(self, message=None):
+    def __init__(self, message=None, fmt=True):
         if not message:
             message = self.default
         elif isinstance(message, Exception):
             message = "{}: {}".format(message.__class__.__name__, message)
-        if self.msgfmt:
+        if self.msgfmt and fmt:
             message = self.msgfmt.format(message)
         Exception.__init__(self, message)