Remove /etc/netplan/01-netcfg.yaml if present
Remove /etc/netplan/01-netcfg.yaml if present

This file is generated by the ISO install, but cloud-init generates
a new config anyway. We should clean this up, but it does no harm

Change-Id: I7ab9112498592a2978a10e73f3ea9e16e151872f

NeCTAR-RC/nectar-images,NeCTAR-RC/nectar-images