chat-hook: remove app-path from hook state when it has no corresponding group, and do not crash in prior upgrade if chat has no group
chat-hook: remove app-path from hook state when it has no corresponding group, and do not crash in prior upgrade if chat has no group

urbit/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,urbit/urbit