www/rt50: Update to 5.0.10

This release fixes the following vulnerabilities:
CVE-2026-44231
CVE-2026-41075
CVE-2026-41076
CVE-2026-6841
CVE-2026-44227
CVE-2026-44230
CVE-2026-44229
CVE-2026-41073

Changelog: https://github.com/bestpractical/rt/releases/tag/rt-5.0.10
(cherry picked from commit c9eb2148d0e97027d1cf79f79c33f416641c5924)