Python/context: python could get invalid bpy.data in scene update handler after

undo.

The way this got updated from the context is a bit unreliable, and for handlers
the update couldn't happen because there is no context passed in. Now it's
updated from setup_app_data, which is where the change actually happens. I left
in the other updates to be sure but they should not be needed anymore.

source/blender/python/intern/bpy_rna.c

@@ -6339,11 +6339,13 @@ PyObject *BPY_rna_module(void)
 
 void BPY_update_rna_module(void)
 {
+	if(rna_module_ptr) {
 #if 0
-	RNA_main_pointer_create(G.main, rna_module_ptr);
+		RNA_main_pointer_create(G.main, rna_module_ptr);
 #else
-	rna_module_ptr->data = G.main; /* just set data is enough */
+		rna_module_ptr->data = G.main; /* just set data is enough */
 #endif
+	}
 }
 
 #if 0