Add hack to set correct date with GPS

The GPS unit has a problem with rollover and is 1024 weeks behind, so
bump the date forward after gpsdate sets it

modules/rhizo_base/files/SysmoBTS/gpsdate.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Set time based on GPS
+
+[Service]
+Type=simple
+EnvironmentFile=/etc/default/gpsdate
+ExecStart=/usr/sbin/gpsdate --no-detach ${GPSDATE_HOST} ${GPSDATE_PORT}
+ExecStopPost=/bin/bash -c "sleep 1; date $(date +%%m%%d%%H%%M%%Y.%%S -d \"+1024 weeks\")"
+
+[Install]
+WantedBy=multi-user.target