Remove redundant feedrate override

The default in ultimaker.def.json is also 45, so this is not necessary.

resources/definitions/ultimaker2.def.json

@@ -89,9 +89,6 @@
         "machine_max_feedrate_z": {
             "default_value": 40
         },
-        "machine_max_feedrate_e": {
-            "default_value": 45
-        },
         "machine_acceleration": {
             "default_value": 3000
         },