restart-server: Ensure we restart process-fts-updates.

This is mostly important in that if you're running this as part of a
follow-up to a failed upgrade, and you don't do this,
process-fts-updates will be left not running, resulting in full-text
search not updating.

scripts/restart-server

@@ -50,5 +50,8 @@ if using_sso.strip() == b'True':
     logging.info("Restarting Apache WSGI process...")
     subprocess.check_call(["pkill", "-f", "apache2", "-u", "zulip"])
 
+if os.path.exists("/etc/supervisor/conf.d/zulip_db.conf"):
+    subprocess.check_call(["supervisorctl", "restart", "process-fts-updates"])
+
 logging.info("Done!")
 print(OKGREEN + "Application restarted successfully!" + ENDC)