x11/xhost: Update to 1.0.8

update x11/xhost to 1.0.8
Add license

This release hardens xhost against corrupted or malicious responses from
the X server, as well as some minor bug & compatibility fixes, and general
janitorial maintenance.

Changelog:
https://lists.x.org/archives/xorg/2019-February/059613.html

PR: 235910
Submitted by: Samy Mahmoudi
Sponsored by: B3 Init (zeising)