Revert "Disable restart of docker"

This reverts commit a400a3dd09.

test/640_proxy_restart_reattaches_test.sh

@@ -42,11 +42,10 @@ run_on $HOST1 sudo kill -KILL $(docker_on $HOST1 inspect --format='{{.State.Pid}
 sleep 1
 check_attached
 
-# Disabled because Docker 1.8 often fails to restart weave or weaveproxy
 # Restart docker itself, using different commands for systemd- and upstart-managed.
-#run_on $HOST1 sh -c "command -v systemctl >/dev/null && sudo systemctl restart docker || sudo service docker restart"
-#wait_for_proxy $HOST1
-#check_attached
+run_on $HOST1 sh -c "command -v systemctl >/dev/null && sudo systemctl restart docker || sudo service docker restart"
+wait_for_proxy $HOST1
+check_attached
 
 # Restarting proxy shouldn't kill unattachable containers
 proxy_start_container $HOST1 -di --name=c3 --restart=always # Use ipam, so it won't be attachable w/o weave