Add ClearActivePGPHash (#6606)
Add ClearActivePGPHash (#6606)

Calling SetActivePGPHash with hash: "" has a side effect of checking if
a key with that hash exist and logging a warning if it doesn't.
keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client,keybase/client