Revert "app: quick/dirty-exit on all releases (not just stable ones) while…"

This reverts commit d22f1c3332.

The memory corruption is fixed, we can restore the original quit code.

app/app.c

@@ -551,36 +551,18 @@ app_exit_after_callback (Gimp         *gimp,
    *  to catch possible problems in our finalizers.
    */
 
-#ifdef GIMP_RELEASE
+#ifdef GIMP_UNSTABLE
+
+  g_application_quit (G_APPLICATION (app));
+
+#else
+
   gimp_gegl_exit (gimp);
 
   gegl_exit ();
 
   exit (gimp_core_app_get_exit_status (GIMP_CORE_APP (app)));
-#else
-  if (g_getenv ("GIMP_DIRTY_EXIT"))
-    {
-      gimp_gegl_exit (gimp);
 
-      gegl_exit ();
-
-      exit (gimp_core_app_get_exit_status (GIMP_CORE_APP (app)));
-    }
-  else
-    {
-      /* Since GLib recent changes removing glice implementation and also in
-       * GType code, we experience crashes during exit. There is a clear memory
-       * corruption going on, but it's extremely hard to diagnose.
-       * We don't want to hide these on development builds, so by default, we
-       * will exit cleanly (with crashes), leaving contributors a chance to look
-       * at it.
-       * With the GIMP_DIRTY_EXIT environment variable, people will be able to
-       * more quickly exit the process, bypassing memory cleanup issues, without
-       * having to rebuild. This way, it's also good to work on other code and
-       * not be bothered by the crashes-on-exit until we find the reasons.
-       */
-      g_application_quit (G_APPLICATION (app));
-    }
 #endif
 
   return FALSE;