Build admin-console against 3.8

Change-Id: I30294dfdd64cfc8ef0c334dad580b96ae79fed9b
diff --git a/jenkins/gerrit-bazel-plugin-admin-console.yaml b/jenkins/gerrit-bazel-plugin-admin-console.yaml
index e186dde..20d8a93 100644
--- a/jenkins/gerrit-bazel-plugin-admin-console.yaml
+++ b/jenkins/gerrit-bazel-plugin-admin-console.yaml
@@ -6,6 +6,7 @@
           branch:
             - master
           gerrit-branch:
+            - stable-3.8
             - stable-3.7
             - stable-3.6
             - stable-3.5