JSON fix: always display support interface extruder (CURA-2308)

The interface extruder determines whether an interface should be enabled

resources/definitions/fdmprinter.def.json

@@ -2495,7 +2495,7 @@
                     "description": "Generate a dense interface between the model and the support. This will create a skin at the top of the support on which the model is printed and at the bottom of the support, where it rests on the model.",
                     "type": "bool",
                     "default_value": false,
-                    "global_inherits_stack": "support_extruder_nr",
+                    "global_inherits_stack": "support_interface_extruder_nr",
                     "enabled": "support_enable",
                     "settable_per_mesh": true
                 },
@@ -3283,7 +3283,7 @@
                             "type": "extruder",
                             "default_value": "0",
                             "value": "support_extruder_nr",
-                            "enabled": "support_enable and machine_extruder_count > 1 and extruderValue(support_interface_extruder_nr, 'support_interface_enable')",
+                            "enabled": "support_enable and machine_extruder_count > 1",
                             "settable_per_mesh": false,
                             "settable_per_extruder": false
                         }