to RESIN_CONNECTABLE* variables
meta-resin 2.14.0 will allow building of one image which by default is unmanaged.
The conversion between managed and unmanaged will be done through the os-config tool
at boot time, based on the existence of resinio configuration parameters in config.json,
so we remove the references to these obsolete variables from here.
Signed-off-by: Florin Sarbu <florin@resin.io>
