Don't allow filament change without homing first (#7054)

Marlin/Marlin_main.cpp

    */
   inline void gcode_M600() {
 
+    // Don't allow filament change without homing first
+    if (axis_unhomed_error()) {
+        home_all_axes();
+    }
+
     // Initial retract before move to filament change position
     const float retract = parser.seen('E') ? parser.value_axis_units(E_AXIS) : 0
       #if defined(PAUSE_PARK_RETRACT_LENGTH) && PAUSE_PARK_RETRACT_LENGTH > 0