Merge from stable/11:
Fix the uninitialized use of source IPv6 address in NAT64LSN. This code is already refactored in head/, but due to the missing epoch(9) support it is impossible to merge. So, it is direct commit to stable/11. Reported by: Patrick M. Hausen <hausen punkt de> Tested by: Patrick M. Hausen <hausen punkt de>
Approved by: re (kib, gjb)