rsi_hw_iface: set RSI IP_NUMBER config to invalid value.
rsi_hw_iface: set RSI IP_NUMBER config to invalid value.

This aligns `ros_rsi_ethernet.xml` with the KR C2 file, and also forces users to set the entry to a valid value.
ivareri/kuka_experimental,cschindlbeck/kuka_experimental,cschindlbeck/kuka_experimental,rtonnaer/kuka_experimental,rtonnaer/kuka_experimental,BrettHemes/kuka_experimental,ivareri/kuka_experimental,ros-industrial/kuka_experimental,BrettHemes/kuka_experimental,tingelst/kuka_experimental,tingelst/kuka_experimental,ros-industrial/kuka_experimental