Document vulnerability for gitlab smaller 1.7.5 and 1.8.2

[mfechner]

Summary

Commit message:
Document new vulnerabilities in www/gitlab < 10.8.2 or < 10.7.5 or < 10.6.6

Test Plan

Create entry with:
make newentry
make validate
pkg audit -f ./vuln.xml gitlab-9.5
pkg audit -f ./vuln.xml gitlab-10.6.5
pkg audit -f ./vuln.xml gitlab-10.6.6
pkg audit -f ./vuln.xml gitlab-10.7.0
pkg audit -f ./vuln.xml gitlab-10.7.4
pkg audit -f ./vuln.xml gitlab-10.7.5
pkg audit -f ./vuln.xml gitlab-10.8.0
pkg audit -f ./vuln.xml gitlab-10.8.1
pkg audit -f ./vuln.xml gitlab-10.8.2