Update language_cz.h

Marlin/language_cz.h

 #define MSG_AUTOSTART                       "Autostart"
 #define MSG_DISABLE_STEPPERS                "Uvolnit motory"
 #define MSG_AUTO_HOME                       "Domovska pozice"
-#define MSG_LEVEL_BED_HOMING                "Homing"
+#define MSG_LEVEL_BED_HOMING                "Mereni podlozky"
 #define MSG_SET_HOME_OFFSETS                "Nastavit ofsety"
 #define MSG_SET_ORIGIN                      "Nastavit pocatek"
 #define MSG_PREHEAT_PLA                     "Zahrat PLA"