12.4 release note: fix for bugs 263574 and 238314

Bug 238314
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=238314
was fixed by a commit with reference to bug 263574
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=263574

PR: 263574, 238314
Approved by: gjb (mentor)
Differential revision: https://reviews.freebsd.org/D37402