[GRASS-translations] po files update

[Carlos Dávila]

Hello all translators
I hope all of you have enjoyed some vacation days and start new year plenty of energy to continue working on your translations.
Markus asked me to update po files for 6.4.0RC2, so I call you to send your translations to the repository (or to me if don't have svn write access) *before next 9th of January about 15:00 GMT*. I
will update po files for all languages after that (unless any translators prefer to do it by themselves). 
Regards
Carlos