[admesh] Out-of-bounds read in admesh

ADMesh through 0.98.4 has a heap-based buffer over-read in stl_update_connects_remove_1 (called from stl_remove_degenerate) in connect.c in libadmesh.a.

References

• https://nvd.nist.gov/vuln/detail/CVE-2018-25033
• https://github.com/admesh/admesh/issues/28
• https://lists.debian.org/debian-lts-announce/2022/05/msg00029.html
• https://github.com/advisories/GHSA-5jrq-582v-9767