specfile: drop dependancy on /etc/system-release

  This will allow users to unistall 'system-release' or 'fedora-release'
  package, thus allowing de-branding of Fedora if needed. For more info:

  https://bugzilla.redhat.com/show_bug.cgi?id=1493479

initscripts.spec

@@ -19,8 +19,6 @@ Conflicts: dmraid < 1.0.0.rc16-18
 Conflicts: policycoreutils < 2.5-6
 Requires: systemd
 Requires: iproute, /sbin/arping, findutils
-# Not strictly required, but nothing else requires it
-Requires: /etc/system-release
 Requires: cpio
 Requires: hostname
 Conflicts: ipsec-tools < 0.8.0-2