rpccache: key on UID too (#18453)
rpccache: key on UID too (#18453)

* rpccache: key on UID too

* fix possible collisions

keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client