Bug#1036062: frr: CVE-2023-31490

[David Lamparter]

Fixed upstream in 9f1ba873637fd6ce4a2d366eafcf41402775852b on stable/8.4
branch.

Debian fix incoming with bump to 8.4.4 if that's OK?  That wouldn't be a
targeted security fix, but FRR minor versions are bugfix-only.


-equi