remove ip fowarding from systemd (fixed: commit #3801)

Docker-DCO-1.1-Signed-off-by: Lokesh Mandvekar <lsm5@redhat.com> (github: lsm5)

contrib/init/systemd/docker.service

@@ -4,8 +4,6 @@ Documentation=http://docs.docker.io
 After=network.target
 
 [Service]
-Type=simple
-ExecStartPre=/usr/sbin/sysctl -w net.ipv4.ip_forward=1 net.ipv6.conf.all.forwarding=1
 ExecStart=/usr/bin/docker -d
 Restart=on-failure