Workaround JENKINS-50470

Change-Id: I56bd4c869389e506b4064c0d8709c9914b69066a
diff --git a/git-mirror-pipeline.groovy b/git-mirror-pipeline.groovy
index 45536d0..8bfe467 100644
--- a/git-mirror-pipeline.groovy
+++ b/git-mirror-pipeline.groovy
@@ -6,7 +6,7 @@
       try{
         def branches = BRANCHES.tokenize(',')
         def pollBranches = []
-        for (i=0; i < branches.size; i++) {
+        for (i=0; i < branches.size(); i++) {
             pollBranches.add([name:branches[i]])
         }
         dir("source") {