devtools/gerrit: backport reviewiers column fix to 3.3.2

Gerrit 3.3.1 seems to have introduced a bug which makes the reviewers
column in the dashboard entry: https://bugs.chromium.org/p/gerrit/issues/detail?id=13899

This adds an override of gerrit.war to our Docker containers. The .war
is pulled over HTTP. It has been manually built by q3k from a source
checkout. The details on how this was done are in the WORKSPACE
http_file archive.

Once 3.3.3 lands we should get rid of it.

Change-Id: I8b64103cb87d8b185ff35165695a18cb19fea523
diff --git a/devtools/gerrit/kube/gerrit.libsonnet b/devtools/gerrit/kube/gerrit.libsonnet
index ba3180a..1a466bd 100644
--- a/devtools/gerrit/kube/gerrit.libsonnet
+++ b/devtools/gerrit/kube/gerrit.libsonnet
@@ -38,7 +38,7 @@
             address: "gerrit@hackerspace.pl",
         },
 
-        tag: "3.3.2-r3",
+        tag: "3.3.2-r4",
         image: "registry.k0.hswaw.net/q3k/gerrit:" + cfg.tag,
         resources: {
             requests: {