fix: no warn when deleting lock file maintenance branch

Closes #1797

lib/workers/branch/index.js

@@ -158,7 +158,7 @@ async function processBranch(branchConfig) {
       !config.parentBranch &&
       branchExists
     ) {
-      logger.warn(
+      logger.info(
         'Deleting lock file maintenance branch as master lock file no longer needs updating'
       );
       return 'delete';