[Reproducible-builds] Bug#792687: gettext: please support timestamps from environment

[Bruno Haible]

A bug has been opened in the Gettext bug tracker about this issue:
https://savannah.gnu.org/bugs/?49654

In my opinion (as former Gettext maintainer) the fix ought to go into
msgfmt, not xgettext.

The gettext.diff.txt patch from
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=792687
is therefore the wrong approach, IMO.

Bruno