Update common.php

Created by: scoid

--> traduction allemande, German translation

@BOUBOULE

4 changes should be made in line 24, 733, 988 and 1051:

"spanish" => "Spanisch", // "german" => "Deutsch",

"Fil d'actualités"=> "Nachrichtenstrom", // this translation should be inversed in the original, do you agree to turn it around? Now it shows French => German, it should be English => German

'Admin public' => "öffentliche Administration", // original French was => "Admin public", not sure of its meaning

"French"=> "Französisch", // you have to add "German"=> "Deutsch" in this array