Fix proxy_http_version.

This happened as a result of a merge conflict introduced in commit 7d9c234e.  I've reviewed the PRs against hsmaster and do not see that commit in any of them.  The conflict was created while I was using a branch called new_parameters_merge where I merged all my separate feature branches into one in order to do some testing
with my test hosts.  That conflict then made its way into hsmaster.

ref.
https://github.com/hubspotdevops/puppet-nginx/commit/7d9c234e35c3eebddcad24f6d08f14926ed9ba63