Update language_de.h

Marlin/language_de.h

 #define MSG_PREHEAT_1                       _UxGT("Vorwärmen PLA")
 #define MSG_PREHEAT_1_N                     _UxGT("Vorwärmen PLA ")
 #define MSG_PREHEAT_1_ALL                   _UxGT("Vorw. PLA Alle")
-#define MSG_PREHEAT_1_END                   _UxGT("Vorw. PLA Extruder")
+#define MSG_PREHEAT_1_END                   _UxGT("Vorw. PLA Extr.")
 #define MSG_PREHEAT_1_BEDONLY               _UxGT("Vorw. PLA Bett")
 #define MSG_PREHEAT_1_SETTINGS              _UxGT("Vorw. PLA Einst.")
 #define MSG_PREHEAT_2                       _UxGT("Vorwärmen ABS")
 #define MSG_PREHEAT_2_N                     _UxGT("Vorwärmen ABS ")
 #define MSG_PREHEAT_2_ALL                   _UxGT("Vorw. ABS Alle")
-#define MSG_PREHEAT_2_END                   _UxGT("Vorw. ABS Extruder")
+#define MSG_PREHEAT_2_END                   _UxGT("Vorw. ABS Extr.")
 #define MSG_PREHEAT_2_BEDONLY               _UxGT("Vorw. ABS Bett")
 #define MSG_PREHEAT_2_SETTINGS              _UxGT("Vorw. ABS Einst.")
 #define MSG_COOLDOWN                        _UxGT("Abkühlen")