Merge pull request #3455 from michos-conradt/RCBugFix

Add missing translations for German

Marlin/language_de.h

 #define MSG_HEATING_COMPLETE                "Aufgeheizt"
 #define MSG_BED_HEATING                     "Bett aufheizen"
 #define MSG_BED_DONE                        "Bett aufgeheizt"
+#define MSG_EXTRUDE                         "Extrudieren"
+#define MSG_BED_Z                           "Bett Z"
+#define MSG_A_TRAVEL                        "A Rueckzug"
+#define MSG_HEATING_FAILED_LCD              "Heizen fehlgesch."
+#define MSG_ERR_REDUNDANT_TEMP              "Redund. Temperaturabw."
+#define MSG_THERMAL_RUNAWAY                 "Temp. n. erreicht"
+#define MSG_ERR_MAXTEMP                     "Temp. ueberschritten"
+#define MSG_ERR_MAXTEMP                     "Temp. unterschritten"
+#define MSG_ERR_MAXTEMP_BED                 "Temp. Bett ueberschr."
+#define MSG_ERR_MAXTEMP_BED                 "Temp. Bett unterschr."
 
 #define MSG_DELTA_CALIBRATE                 "Delta kalibrieren"
 #define MSG_DELTA_CALIBRATE_X               "Kalibriere X"