fix, PEBKAC, use sa's scope id for ipv6 mreq interface number

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'core/api' into next

* core/api:
  fix, PEBKAC, use sa's scope id for ipv6 mreq interface number
Merge branch 'next'

* next:
  fix, PEBKAC, use sa's scope id for ipv6 mreq interface number