Remove forgotten (?) undef at the end of menu.cpp

Firmware/menu.cpp

@@ -553,4 +553,4 @@ uint8_t menu_item_edit_P(const char* str, T pval, int16_t min_val, int16_t max_v
 template uint8_t menu_item_edit_P<int16_t*>(const char* str, int16_t *pval, int16_t min_val, int16_t max_val);
 template uint8_t menu_item_edit_P<uint8_t*>(const char* str, uint8_t *pval, int16_t min_val, int16_t max_val);
 
-#undef _menu_data
+