security/doas: Update to 5.9p5

This update enforces the correct uid and gid when -u switch is used.

PR: 211622
Reported by: telnetuserid@sdf.org
Submitted by: jsmith@resonatingmedia.com (maintainer)
Approved by: koobs, adamw (mentors)
Relnotes: https://github.com/slicer69/doas/releases/tag/v5.9-5
Differential Revision: https://reviews.freebsd.org/D7630