Add the unspecified address check for DNS6 StationIp,
so the underlying driver will choose the source address.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18017 6f19259b-4bc3-4df7-8a09-765794883524