rtpengine.service : added new service file for Centos

added new systemd service file for Centos 7

el/rtpengine.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=NGCP RtpEngine - RTP Media Proxy
+Wants=network-online.target
+After=network-online.target
+
+[Service]
+Type=forking
+User=ngcp-rtpengine
+Group=daemon
+Environment=CFGFILE=/etc/rtpengine/rtpengine.conf
+EnvironmentFile=/etc/sysconfig/rtpengine
+PIDFile=/var/run/rtpengine.pid
+ExecStart=/usr/sbin/rtpengine --config-file=${CFGFILE} --interface=${INTERFACE} --listen-ng=${LISTEN_UDP} --log-facility=${LOG_FACILITY} --log-level=${LOG_LEVEL}
+Restart=on-failure
+
+[Install]
+WantedBy=multi-user.target