keep d.Network as a string so we don't cause pre-existing vmware machines to make machine panic
keep d.Network as a string so we don't cause pre-existing vmware machines to make machine panic

Signed-off-by: Sven Dowideit <6f6969dc7db01e7204496bfb27e43d63ec4b2eb3@home.org.au>

londoncalling/machine,Herbis/machine,dgageot/machine,SvenDowideit/machine,SvenDowideit/machine,ibuildthecloud/machine,docker/machine,exoscale/docker-machine,dweomer/docker-machine,londoncalling/machine,exoscale/docker-machine,dweomer/docker-machine,docker/machine,dgageot/machine,Herbis/machine,voutilad/machine,ibuildthecloud/machine,voutilad/machine