I18n: Update translation oc (75%).
I18n: Update translation oc (75%).

21 translated messages, 7 untranslated messages.

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

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