Arch: Fix ArchWall onBeforeChange

The onBeforeChange method in the ArchWall class did not call onBeforeChange from its parent class. This blocked the 'MoveWithHost' behavior of windows placed in walls.

src/Mod/Arch/ArchWall.py

@@ -988,6 +988,8 @@ class _Wall(ArchComponent.Component):
         If "Length" has changed, record the old length so that .onChanged() can
         be sure that the base needs to be changed.
 
+        Also call ArchComponent.Component.onBeforeChange().
+
         Parameters
         ----------
         prop: string
@@ -996,6 +998,7 @@ class _Wall(ArchComponent.Component):
 
         if prop == "Length":
             self.oldLength = obj.Length.Value
+        ArchComponent.Component.onBeforeChange(self,obj,prop)
 
     def onChanged(self, obj, prop):
         """Method called when the object has a property changed.