CA-50488: When adding a VIF to a bridge, if there are any non-virtual interfaces reflect the carrier. If there are only virtual interfaces (a virtual network) then we always consider a carrier is present.
CA-50488: When adding a VIF to a bridge, if there are any non-virtual interfaces reflect the carrier. If there are only virtual interfaces (a virtual network) then we always consider a carrier is present.

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@eu.citrix.com>
Reviewed-by: Matthias Goergens <bc66cfc3364dde487c6cd1d5e0a8c91a454ed3da@gmail.com>
Reviewed-by: Rob Hoes <8783b3376fb07d39edffc8d7da68a6de3874a7e6@citrix.com>

djs55/xcp-networkd,koushikcgit/xcp-rrdd,simonjbeaumont/xcp-rrdd,djs55/xcp-networkd,koushikcgit/xcp-rrdd,sharady/xcp-networkd,sharady/xcp-networkd,djs55/xcp-rrdd,koushikcgit/xcp-networkd,djs55/xcp-rrdd,koushikcgit/xcp-networkd,robhoes/squeezed,djs55/squeezed,johnelse/xcp-rrdd,simonjbeaumont/xcp-rrdd,koushikcgit/xcp-rrdd,johnelse/xcp-rrdd