rpm: Update spec file to use systemd macros, close bug redhat bug 1013999, contributed by Juan Orti Alcaine

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10937 ddefafc4-47db-0310-ae44-fa13212b10f2
rpm: using systemd macros (backported from main)

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/branches/resiprocate-1.9@10938 ddefafc4-47db-0310-ae44-fa13212b10f2