Change translation

I change the translation for the 3 languages. German has to be checked since I used Google translate to get the translation.

app/i18n/de/gen.php

@@ -156,7 +156,7 @@ return array(
 		'damn' => 'Verdammt!',
 		'default_category' => 'Unkategorisiert',
 		'no' => 'Nein',
-		'not_applicable' => 'N/A',
+		'not_applicable' => 'Nicht verfügbar',
 		'ok' => 'OK!',
 		'or' => 'oder',
 		'yes' => 'Ja',

app/i18n/en/gen.php

@@ -156,7 +156,7 @@ return array(
 		'damn' => 'Damn!',
 		'default_category' => 'Uncategorized',
 		'no' => 'No',
-		'not_applicable' => 'N/A',
+		'not_applicable' => 'Not available',
 		'ok' => 'Ok!',
 		'or' => 'or',
 		'yes' => 'Yes',

app/i18n/fr/gen.php

@@ -156,7 +156,7 @@ return array(
 		'damn' => 'Arf !',
 		'default_category' => 'Sans catégorie',
 		'no' => 'Non',
-		'not_applicable' => 'N/A',
+		'not_applicable' => 'Non disponible',
 		'ok' => 'Ok !',
 		'or' => 'ou',
 		'yes' => 'Oui',