ci: Remove unnecessary steps from production upgrade script.

This removes some steps which are no longer necessary to be run
in the production upgrade script. The steps were used due to
errors related to supervisor failing to restart which was resolved
in the commit 08c39a7388.

tools/ci/production-upgrade

@@ -11,13 +11,12 @@ set -x
 # need to do some preparatory steps. It is a goal to delete these
 # steps.
 
-# Reinstall rabbitmq-server and supervisor.
+# Reinstall rabbitmq-server.
 #
 # * For rabbitmq-server, we likely need to do this to work around the
 # hostname changing on reboot causing RabbitMQ to not boot.
-# * For supervisor, we don't understand why it doesn't start properly.
-sudo apt-get -y purge rabbitmq-server supervisor
-sudo apt-get -y install rabbitmq-server supervisor
+sudo apt-get -y purge rabbitmq-server
+sudo apt-get -y install rabbitmq-server
 
 # Start the postgresql service.
 sudo service postgresql start
@@ -29,20 +28,8 @@ if ! sudo service rabbitmq-server start; then
     sudo service rabbitmq-server start
 fi
 
-# Apply puppet (still on the previous release the container was
-# installed with).  This should leave us with a working copy of Zulip
-# running a previous release.
-sudo /home/zulip/deployments/current/scripts/zulip-puppet-apply -f
-
-# Stopping nginx service started by above command.
-#
-# This is a workaround for an unexpected `Unable to stop
-# Service[nginx]` error in the puppet apply step of upgrade otherwise.
-if ! sudo service nginx stop; then
-    echo
-    echo "Stoping nginx failed. Trying again:"
-    sudo service nginx stop
-fi
+# Start the supervisor
+sudo service supervisor start
 
 # Zulip releases before 2.1.8/3.5/4.4 have a bug in their
 # `upgrade-zulip` scripts, resulting in them exiting with status 0