set support brim width to 3 line widths

PP-249

resources/definitions/ultimaker.def.json

@@ -112,6 +112,7 @@
         "speed_slowdown_layers": { "value": 1 },
         "speed_travel_layer_0": { "value": "speed_travel" },
         "support_brim_enable": { "value": "True" },
+        "support_brim_width": { "value": "skirt_brim_line_width * 3"},
         "support_infill_rate": { "value": "0 if support_structure == 'tree' else 80 if gradual_support_infill_steps != 0 else 15" },
         "support_initial_layer_line_distance": { "minimum_value_warning": "0 if support_structure == 'tree' else support_line_width" },
         "support_interface_height": { "value": "2 * layer_height" },