chore: error not warn when repository not found

lib/workers/repository/error.js

@@ -31,7 +31,7 @@ async function handleError(config, err) {
     return err.message;
   } else if (err.message === 'not-found') {
     delete config.branchList; // eslint-disable-line no-param-reassign
-    logger.warn('Repository is not found');
+    logger.error('Repository is not found');
     return err.message;
   } else if (err.message === 'fork') {
     logger.info('Repository is a fork and not manually configured - skipping');