gpo: During restore clobber GPT.INI with a blank version

gpo: During restore clobber GPT.INI with a blank version

Generally speaking, there is not much value to keeping this file. The
display name does not ever seem to be used and the version only applies
to the original domain or DC it was on. The command line option to
revert this behaviour is mostly for the tests or for having a straight
1:1 backup-restore for pure restoration.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13806

Signed-off-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>