allow to toggle features in backend

store/sql_store.go

@@ -148,6 +148,8 @@ func NewSqlStore() Store {
 	sqlStore.webhook.(*SqlWebhookStore).CreateIndexesIfNotExists()
 	sqlStore.preference.(*SqlPreferenceStore).CreateIndexesIfNotExists()
 
+	sqlStore.preference.(*SqlPreferenceStore).DeleteUnusedFeatures()
+
 	if model.IsPreviousVersion(schemaVersion) || isSchemaVersion07 || isSchemaVersion10 {
 		sqlStore.system.Update(&model.System{Name: "Version", Value: model.CurrentVersion})
 		l4g.Warn("The database schema has been upgraded to version " + model.CurrentVersion)