Update app_languages.php (#2433)

Fix quotes

core/default_settings/app_languages.php

@@ -369,7 +369,7 @@ $text['label-center']['he'] = "מֶרְכָּז";
 $text['label-center']['uk'] = "центр";
 $text['label-center']['sv-se'] = "Centrum";
 $text['label-center']['de-de'] = "Mitte";
-$text['label-center']['de-at'] = "Mitte;
+$text['label-center']['de-at'] = "Mitte";
 $text['label-center']['ro'] = "Centru";
 $text['label-center']['fa'] = "";
 $text['label-center']['ar-eg'] = "مركز";