I18n: Update translation el (71%).
I18n: Update translation el (71%).

20 translated messages, 8 untranslated messages.

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

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