e - fix leak added by previous fix for icon theme

fixes leak added by a885c8c040

though this is basically unlikely to happen and happens likely just
once for an app... so not a big deal

@fix

src/bin/e_config.c

@@ -75,7 +75,7 @@ _e_config_cb_efreet_cache_update(void *data EINA_UNUSED, int type EINA_UNUSED, v
           {
              if (!efreet_icon_theme_find(e_config->icon_theme))
                {
-                  e_config->icon_theme = eina_stringshare_add("hicolor");
+                  eina_stringshare_replace(&e_config->icon_theme, "hicolor");
                   e_config_save_queue();
                }
           }