[installer] [host] remove initialisation within class for SupportedDevice
[installer] [host] disable the correct radio button if NFS is selected;
check that NFS has been selected, not that it is supported, when disabling
wireless
[installer] [host] fix CSS for border around QGroupBox
[installer] [host] fix bug where wireless is displayed if advanced
settings chosen but wired chosen
[installer] [host] use the local mirror file for our downloadable image