net/ndisc6: Fix build failure for 13.x-RELEASE and Add ja_JP locale
Fixed build failures in 13.x-RELEASE.
Changed MASTER_SITES to https.
PR: 288977
MFH: 2026Q2
Event: Wiesbaden Hackathon 202604
(cherry picked from commit 24b17c7630e551584636340addbc156a199aa532)