Fix issues with makeblock definition

resources/definitions/makeblock_mcreate.def.json

@@ -53,7 +53,7 @@
             "default_value": "Marlin"
         },
         "gantry_height": {
-            "default_value": 15.0
+            "value": 15.0
         },
         "machine_extruder_count": {
             "default_value": 1

resources/extruders/makeblock_mcreate_extruder_0.def.json

@@ -1,5 +1,4 @@
 {
-    "id": "makeblock_extruder_0",
     "version": 2,
     "name": "Extruder 1",
     "inherits": "fdmextruder",