Use officially released gerrit.war as default

So far the latest successful CI build was by default built into the
docker images. This could potentially be quite unstable.

With this change the default is download the war-file from the official
release page.

Change-Id: I365002f1ed5b8a9bc1ea77944e885cae8a1adb23
diff --git a/container-images/gerrit-base/Dockerfile b/container-images/gerrit-base/Dockerfile
index d360860..9bae02a 100644
--- a/container-images/gerrit-base/Dockerfile
+++ b/container-images/gerrit-base/Dockerfile
@@ -13,7 +13,7 @@
     mkdir -p /var/war
 
 # Download Gerrit release
-ARG GERRIT_WAR_URL=https://gerrit-ci.gerritforge.com/view/Gerrit/job/Gerrit-bazel-stable-2.16/lastSuccessfulBuild/artifact/gerrit/bazel-bin/release.war
+ARG GERRIT_WAR_URL=https://gerrit-releases.storage.googleapis.com/gerrit-2.16.9.war
 RUN curl -k -o /var/war/gerrit.war ${GERRIT_WAR_URL} && ln -s /var/war/gerrit.war /var/gerrit/bin/gerrit.war
 
 # Allow incoming traffic