Treat contact lookups as successful if user is found but chat is not

telegram/utils.go

@@ -78,7 +78,12 @@ func (c *Client) GetContactByID(id int64, chat *client.Chat) (*client.Chat, *cli
 				ChatId: id,
 			})
 			if err != nil {
-				return nil, nil, err
+				// error is irrelevant if the user was found successfully
+				if user == nil {
+					return nil, nil, err
+				} else {
+					return nil, user, nil
+				}
 			}
 
 			c.cache.chats[id] = cacheChat