Lower warning values for retraction speeds

As discussed with David, the warning should really be quite a bit lower. No printers actually reach 100.

Contributes to issue CURA-2284.

resources/definitions/fdmprinter.def.json

@@ -1161,7 +1161,7 @@
                     "default_value": 25,
                     "minimum_value": "0",
                     "maximum_value": "machine_max_feedrate_e",
-                    "maximum_value_warning": "100",
+                    "maximum_value_warning": "25",
                     "enabled": "retraction_enable",
                     "settable_per_mesh": false,
                     "settable_per_extruder": true,
@@ -1174,7 +1174,7 @@
                             "default_value": 25,
                             "minimum_value": "0",
                             "maximum_value": "machine_max_feedrate_e",
-                            "maximum_value_warning": "100",
+                            "maximum_value_warning": "25",
                             "enabled": "retraction_enable",
                             "value": "retraction_speed",
                             "settable_per_mesh": false,
@@ -1188,7 +1188,7 @@
                             "default_value": 25,
                             "minimum_value": "0",
                             "maximum_value": "machine_max_feedrate_e",
-                            "maximum_value_warning": "100",
+                            "maximum_value_warning": "25",
                             "enabled": "retraction_enable",
                             "value": "retraction_speed",
                             "settable_per_mesh": false,