elm_external: shutdown elm after del callback

This fixes a crash in edje_inspector as:
- delete callback is called on the object
 --> this unloaded elm
- destructor is called on the object
 --> this did some elm stuff, in particular read the config
     from _elm_config (now NULL).

Instead, shutdown elm after del, during free.

Also reset hash pointer to NULL after free.

legacy/elementary/src/edje_externals/elm.c

@@ -31,15 +31,6 @@ external_elm_shutdown(void)
    elm_shutdown();
 }
 
-static void
-_external_obj_del(void *data EINA_UNUSED, Evas *evas EINA_UNUSED,
-                  Evas_Object *obj, void *event_info EINA_UNUSED)
-{
-   evas_object_event_callback_del(obj, EVAS_CALLBACK_DEL,
-                                  _external_obj_del);
-   external_elm_shutdown();
-}
-
 void
 external_signal(void *data EINA_UNUSED, Evas_Object *obj, const char *sig,
                 const char *source)
@@ -106,6 +97,7 @@ _external_signal_proxy_free_cb(void *data, Evas *e EINA_UNUSED,
                                void *event_info EINA_UNUSED)
 {
    Elm_External_Signals_Proxy_Context *ctxt = data;
+   external_elm_shutdown();
    free(ctxt);
 }
 
@@ -201,8 +193,6 @@ external_signals_proxy(Evas_Object *obj, Evas_Object *edje, const char *part_nam
         evas_object_smart_callback_add
            (obj, d->name, _external_signal_proxy_cb, ctxt);
      }
-   evas_object_event_callback_add(obj, EVAS_CALLBACK_DEL,
-                                  _external_obj_del, NULL);
 }
 
 void

legacy/elementary/src/lib/elm_config.c

@@ -3574,6 +3574,5 @@ _elm_config_shutdown(void)
 
    _desc_shutdown();
 
-   if (_elm_key_bindings)
-     eina_hash_free(_elm_key_bindings);
+   ELM_SAFE_FREE(_elm_key_bindings, eina_hash_free);
 }