I18n: Update translation ar (53%).
I18n: Update translation ar (53%).

15 translated messages, 13 untranslated messages.

Transifex (https://www.transifex.com/xfce/public/).

xfce-mirror/xfce4-genmon-plugin,xfce-mirror/xfce4-genmon-plugin,xfce-mirror/xfce4-genmon-plugin