Update VuXML entry for xorg-server issues

Update VuXML entry for xorg-server issues related to CVE-2017-10971 and
CVE-2017-10972. The version check was wrong missing the portepoch which
meant that the entry never matched anything. It was also only added for
xorg-server 1.19, while we have 1.18 in base.

Fix formatting and edit the overly long lines.