Remove nonsensical global nozzle offsets for Dagoma DiscoEasy200

It doesn't make sense to always have a nozzle offset for all nozzles. What's more, the setting only exists in fdmextruder.def.json so it can't be set in something that inherits from fdmprinter.def.json.

README.md

@@ -63,7 +63,7 @@ There are two ways of doing it. You can either use the generator [here](http://q
 * Set your machine's dimensions with machine_width, machine_depth, and machine_height
 * If your printer's origin is in the center of the bed, set machine_center_is_zero to true.
 * Set your print head dimensions with the machine_head_shape parameters
-* Set the nozzle offset with machine_nozzle_offset_x_1 and machine_nozzle_offset_y1
+* Set the nozzle offset with machine_nozzle_offset_x and machine_nozzle_offset_y
 * Set the start and end gcode in machine_start_gcode and machine_end_gcode
 * If your printer has a heated bed, set visible to true under material_bed_temperature
 

resources/definitions/dagoma_discoeasy200.def.json

@@ -40,12 +40,6 @@
         "gantry_height": {
             "default_value": 55
         },
-        "machine_nozzle_offset_x_1": {
-            "default_value": 18
-        },
-        "machine_nozzle_offset_y_1": {
-            "default_value": 0
-        },
         "machine_gcode_flavor": {
             "default_value": "RepRap"
         },