security/xray-core: Fix rc.d script
It needs to use load_rc_config before knob variables, otherwise
customizations such as config and log path won't work.
PR: 291704
Approved by: Kirill Lebedev <kirill@drlebedev.com> (maintainer)
MFH: 2025Q4
(cherry picked from commit f457dfab6526cd4bd8d137024d2057444b637d9d)