multimedia/vlc: Turn off ASLR

Starting with 13.2, elf processes will have ASLR turned on by default.
However, the vlc binary core dumps with ASLR on, so turn it off until a
proper fix can be found.

This fix is based on a discussion between emaste and Peter
<pmc@citylink.dinoex.sub.org>.

See also: https://lists.freebsd.org/archives/freebsd-stable/2023-March/001181.html
PR: 270038

Reviewed by: emaste, mjg, riggs
Approved by: multimedia (tcberner, maintainer)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D38994