test: fix one more test

remove 500-embed.tpl

test/mocks/databasemock.js

@@ -252,6 +252,7 @@ async function enableDefaultPlugins() {
 	const defaultEnabled = [
 		'nodebb-plugin-dbsearch',
 		'nodebb-widget-essentials',
+		'nodebb-plugin-composer-default',
 	].concat(testPlugins);
 
 	winston.info('[install/enableDefaultPlugins] activating default plugins', defaultEnabled);