shouldAddServiceIP() checks BGPAttachIPToInterface on a per-service
config struct. NewInstance() builds that struct fresh for each Service,
copying over most fields from the global config, missing this one. As
a result the flag has no effect regardless of its value, and BGP-mode
Service VIPs are never bound to the interface.
Copy the field at both construction sites where it's built, and add
a regression test covering the propagation.
Signed-off-by: Justin Cichra <jrcichra@yahoo.com>
2b126dceed