www/gitlab: Update from 10.1.4 to 10.1.5

Also:

• remove %%RUBY_SUFFIX%% from plist (thanks to swills)
• fix broken dependency to rubygem-pg in Gemfile
• fix broken dependency to rubygem-mysql2 in Gemfile
• Add support for reverse proxies in rc script
• Fix: gitlab starts even if gitlab_enable is not set
• Make default listenAddr configurable

PR: 224232 222896 220126 218388
Submitted by: swills, gdinolt@pacbell.net, max@mober.at, Marián Černý <majo-bugs.freebsd.org@cerny.sk>
Reviewed by: tz
Approved by: maintainer
Differential Revision: https://reviews.freebsd.org/D12376