SignalAPI: do not remove the bot itself in update_group_members()

main.py

@@ -114,6 +114,9 @@ class SignalAPI:
             if member not in other_members:
                 members_to_remove.append(member)
 
+        if self.number in members_to_remove:
+            members_to_remove.remove(self.number)
+
         if len(members_to_add) > 0:
             add_result = self.add_group_members(group_id, members_to_add)
             if add_result.is_err():