fix, define UD_NETWORK_SERVICE and UD_MCAST6_* in unserding.h unconditionally

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

* core/api:
  fix, define UD_NETWORK_SERVICE and UD_MCAST6_* in unserding.h unconditionally
Merge branch 'next'

* next:
  fix, define UD_NETWORK_SERVICE and UD_MCAST6_* in unserding.h unconditionally