services: change restart policy to unless-stopped

when we stop an app, the service containers are stopped. they
start running again on reboot.

correct restart policy is "unless-stopped" for all the containers.

src/mailserver.js

@@ -175,7 +175,7 @@ async function configureMail(mailFqdn, mailDomain, serviceConfig) {
     const cmd = serviceConfig.recoveryMode ? '/bin/bash -c \'echo "Debug mode. Sleeping" && sleep infinity\'' : '';
     const logLevel = serviceConfig.recoveryMode ? 'data' : 'info';
 
-    const runCmd = `docker run --restart=always -d --name=mail \
+    const runCmd = `docker run --restart=unless-stopped -d --name=mail \
                 --net cloudron \
                 --net-alias mail \
                 --log-driver syslog \