fix(bundler): catch authentication requirement

lib/manager/bundler/artifacts.js

@@ -166,8 +166,9 @@ async function getArtifacts(
       throw new Error('bundler-fs');
     }
     if (
-      err.stdout &&
-      err.stdout.includes('Please supply credentials for this source')
+      (err.stdout &&
+        err.stdout.includes('Please supply credentials for this source')) ||
+      (err.stderr && err.stderr.includes('Authentication is required'))
     ) {
       logger.warn(
         { err },