net/asterisk20: Update 20.15.0 => 20.15.1 (security fix)
Changelog:
https://downloads.asterisk.org/pub/telephony/asterisk/releases/ChangeLog-20.15.1.html
Security: GHSA-mrq5-74j5-f5cr
Security: GHSA-v9q8-9j8m-5xwp
Sponsored by: FLEX-IT LLC
PR: 288615
Approved by: yuri@ (Mentor)
MFH: 2025Q3
(cherry picked from commit d63aab956a209ad8efc14effe9d132d1e398ed88)