Translation updates to fix build failures

Now that msgfmt is run with -c by default, older versions of gettext are
complaining about the PO headers Last-Translator and Language-Team
still having their default values.  Newer gettext versions fail to catch
this because of a bug (https://savannah.gnu.org/bugs/?40261), which is
why this hasn't been noticed before.

Copy updated versions of affected translation files from the
pgtranslations repository, were those files have been fixed.