JSON fix: flow temp graph reenabled (CURA-1174)

resources/definitions/fdmprinter.def.json

@@ -1060,10 +1060,9 @@
                 {
                     "label": "Flow Temperature Graph",
                     "description": "Data linking material flow (in mm3 per second) to temperature (degrees Celsius).",
-                    "unit": "",
+                    "unit": "[[mm³,°C]]",
                     "type": "str",
                     "default_value": "[[3.5,200],[7.0,240]]",
-                    "enabled": "False",
                     "comments": "old enabled function: material_flow_dependent_temperature",
                     "settable_per_mesh": false,
                     "settable_per_extruder": true