net/xrdp: Update to 0.9.8

[meta]

Summary

Also, update audio/pulseaudio-module to the latest release 0.2.
pulseaudio-module-xrdp 0.2 no longer have build time dependency on xrdp.
Accordingly, add runtime dependency on pulseaudio-module-xrdp to xrdp to
enable audio redirection by default it doesn't cause circular dependency
now.

While here,

• Pet portlint
• Swich PORTVERSION to DISTVERSION

Approved by: ? (mentor)
Relnotes: https://github.com/neutrinolabs/xrdp/releases/tag/v0.9.8
#Differential Revision: https://reviews.freebsd.org/D17326

Test Plan

• portlint looks fine
• poudriere testbuild finished fine
• confirmed application actually works perfectly

[pi]

Approved. Thanks!