reject blank TLF names early in process CORE-4563 (#5768)
reject blank TLF names early in process CORE-4563 (#5768)

* reject blank TLF names early in process

* reject in PostLocal too

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