Check that path exists

posts.py

@@ -6154,9 +6154,11 @@ def download_announce(session, base_dir: str, http_prefix: str,
                              base_dir, nickname, domain, post_id,
                              recent_posts_cache)
             return None
+
         announced_actor = announced_json['id']
         if announced_json.get('attributedTo'):
             announced_actor = get_attributed_to(announced_json['attributedTo'])
+
         if not announced_json.get('type'):
             print('WARN: announced post does not have a type ' +
                   str(announced_json))

utils.py

@@ -745,6 +745,9 @@ def get_locked_account(actor_json: {}) -> bool:
 def has_users_path(path_str: str) -> bool:
     """Whether there is a /users/ path (or equivalent) in the given string
     """
+    if not path_str:
+        return False
+
     users_list = get_user_paths()
     for users_str in users_list:
         if users_str in path_str: