gitlab: Sync gitlab-parameters.cfg to upstream

I manually reviewed

    $ git diff 8.5.1+ce.0-1-ge732b39..8.6.5+ce.0-0-g342f8be --  \
        files/gitlab-config-template/gitlab.rb.template \
        files/gitlab-cookbooks/gitlab/attributes/default.rb

in omnibus-gitlab, and module proxy_cache and http2 changes, which we
already handled in 2 previous patches, there is nothing more interesting
for us.

software/gitlab/gitlab-parameters.cfg

@@ -6,7 +6,7 @@
 #
 # TODO better autogenerate from ^^^ (?)
 #
-# (last updated for omnibus-gitlab 8.5.1+ce.0-1-ge732b39)
+# (last updated for omnibus-gitlab 8.6.5+ce.0-0-g342f8be)
 
 [gitlab-parameters]
 configuration.external_url              = http://lab.example.com

software/gitlab/software.cfg

@@ -235,7 +235,7 @@ md5sum  = 56b135596e013c02bda5555dda6b376b
 
 [gitlab-parameters.cfg]
 <= download-file
-md5sum  = b04b72949f0b9b5da96870ffbf8c1ff4
+md5sum  = 8cbcdb8d9e942df67d2fbb4db5fbfaad
 
 [gitlab-shell-config.yml.in]
 <= download-template