Revert "reenable alternate_walls"

This reverts commit 9b43ab3ad756de3d6f0e1e855bfc5af1928db21f.

The material_alternate_walls setting was supposed to be disabled.
Something to do with hardware.
See CURA- 8079

resources/definitions/fdmprinter.def.json

@@ -7913,7 +7913,7 @@
                     "description": "Alternate wall directions every other layer and inset. Useful for materials that can build up stress, like for metal printing.",
                     "type": "bool",
                     "default_value": false,
-                    "enabled": true,
+                    "enabled": false,
                     "settable_per_mesh": true,
                     "settable_per_extruder": true
                 },