use pre-released features

webapp/components/user_settings/user_settings_advanced.jsx

@@ -51,6 +51,10 @@ const holders = defineMessages({
     EMBED_TOGGLE: {
         id: 'user.settings.advance.embed_toggle',
         defaultMessage: 'Show toggle for all embed previews'
+    },
+    SLASHCMD_AUTOCMP: {
+        id: 'user.settings.advance.slashCmd_autocmp',
+        defaultMessage: 'Enable external application to offer slash command autocomplete'
     }
 });