fix: use unauthenticated URL to check if branch is up to date

In case the authentication token provided is unauthorized the call to `isBranchUpToDate` will fail due to lack of read permission if that URL is used. As a result the error about outdated local branch will be reported instead of the one about missing permission.
By using the original (unauthenticated) URL `isBranchUpToDate` shouldn't fail due to permission as it requires only read permissions, that are necessarly present as the CI wass able to clone the repo.

index.js

@@ -59,7 +59,7 @@ async function run(options, plugins) {
   try {
     await verifyAuth(options.repositoryUrl, options.branch);
   } catch (err) {
-    if (!(await isBranchUpToDate(options.repositoryUrl, options.branch))) {
+    if (!(await isBranchUpToDate(options.branch))) {
       logger.log(
         "The local branch %s is behind the remote one, therefore a new version won't be published.",
         options.branch