This should fix [#31835] "OBJ Importer corrupts a model (crash in edit mode)"...

This should fix [#31835] "OBJ Importer corrupts a model (crash in edit mode)" reported by paul geraskin.

The importer did the mesh validation before calculating edges (should be the other way around).
Reviewed by Campbell.

io_scene_obj/import_obj.py

@@ -672,8 +672,8 @@ def create_mesh(new_objects,
 #                 me_edges[ed].flag |= SHARP
 #         del SHARP
 
-    me.validate()
     me.update(calc_edges=use_edges)
+    me.validate()
 
     ob = bpy.data.objects.new("Mesh", me)
     new_objects.append(ob)