files/fail2ban-openrc.conf: add back the "-x" example.

I've removed the stale socket cleanup from our OpenRC service script:

  * Cleaning up stale sockets isn't really the job of the service script.
  * The ability to ignore a stale socket is already built into the server.

With it gone, maybe the "-x" is a useful example to have in the conf
file (although it's commented-out by default, anyway).

files/fail2ban-openrc.conf

@@ -1,2 +1,2 @@
 # For available options, plase run "fail2ban-server --help".
-#FAIL2BAN_OPTIONS=""
+#FAIL2BAN_OPTIONS="-x"