Ticket 47491 - Update systemd service file to use PartOf directive

Replaced "BindTo" with "PartOf", also removed "After=" which not needed.

https://fedorahosted.org/389/ticket/47491

Reviewed by: richm(Thanks!)

wrappers/systemd.template.service.in

@@ -14,8 +14,7 @@
 # systemctl (re)start @systemdgroupname@
 [Unit]
 Description=@capbrand@ Directory Server %i.
-BindTo=@systemdgroupname@
-After=@systemdgroupname@
+PartOf=@systemdgroupname@
 
 [Service]
 Type=forking