Use archive-ci.gerritforge.com for downloading plugins

Gerrit 3.1 is now EOL and all plugins for creating the local test
environment should be downloaded from the archive-ci site.

Change-Id: I13f44945d1199f9fb2d4bbee7c25524df950bbbd

setup_local_env/setup.sh

diff --git a/setup_local_env/setup.sh b/setup_local_env/setup.sh
index 87af305..777e7fc 100755
--- a/setup_local_env/setup.sh
+++ b/setup_local_env/setup.sh
@@ -17,7 +17,7 @@
 
 SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
 GERRIT_BRANCH=stable-3.1
-GERRIT_CI=https://gerrit-ci.gerritforge.com/view/Plugins-$GERRIT_BRANCH/job
+GERRIT_CI=https://archive-ci.gerritforge.com/view/Plugins-$GERRIT_BRANCH/job
 LAST_BUILD=lastSuccessfulBuild/artifact/bazel-bin/plugins
 EVENTS_BROKER_VER=`grep 'com.gerritforge:events-broker' $(dirname $0)/../external_plugin_deps.bzl | cut -d '"' -f 2 | cut -d ':' -f 3`