chat-cli: skip catch-up if chat-store not booted
This way we don't just crash on the scry that follows.
::
++ catch-up
^- (quip card _state)
+ ?. .^(? %gu /(scot %p our.bowl)/chat-store/(scot %da now.bowl))
+ [~ state]
=/ =inbox
(scry-for inbox %chat-store /all)
|- ^- (quip card _state)
