for BIND* exports, append trailing . to name when

name is identical to the zone.

before:
example.com   TXT "same record"    <-  effective BIND name: example.com.example.com.

after
example.com.  TXT "same record"    <-  effective BIND name: example.com.

It's unlikely the user meant for the former, and if they really do want that, they can manually specify it.