I18n: Update translation ast (78%).

55 translated messages, 15 untranslated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).
I18n: Update translation ast (80%).

56 translated messages, 14 untranslated messages.

Transifex (https://www.transifex.com/projects/p/xfce/).