Remove refspec from gitiles webapp yaml file

Reason is because it was looking at refs/changes/ which meant
that it was also not finding refs/heads/master when it was trying build.

Change-Id: I0b0573f53fdcb332e48788f32358d8f87e137577
diff --git a/jenkins/gitiles-webapp.yaml b/jenkins/gitiles-webapp.yaml
index 26d58e0..d9eb5b9 100644
--- a/jenkins/gitiles-webapp.yaml
+++ b/jenkins/gitiles-webapp.yaml
@@ -20,7 +20,6 @@
     scm:
       - git:
          url: https://gerrit.googlesource.com/gitiles
-         refspec: +refs/changes/*:refs/remotes/origin/*
          branches:
            - master
          skip-tag: true