workspace: Don't relocate sticky windows

Windows are relocated before their workspace is removed, however this
is only necessary for windows that are *only* on that workspace; for
windows on all workspaces, that step is annoying as it will unset the
sticky state requested by the user.

https://bugzilla.gnome.org/show_bug.cgi?id=737625

src/core/workspace.c

@@ -366,7 +366,7 @@ meta_workspace_relocate_windows (MetaWorkspace *workspace,
     {
       MetaWindow *window = l->data;
 
-      if (!window->override_redirect)
+      if (!window->on_all_workspaces)
         meta_window_change_workspace (window, new_home);
     }