Added missing uwsgi_params HTTPS

[ajcrowe]

This is in the default uwsgi_params file but is missing from the template. I see #767 will add custom params, but I think this should be in the defaults

[bastelfreak]

Hi @ajcrowe, thanks for the PR. are you able to add spec tests for it?

[wyardley]

Note that #855 also deals with this, specifically, it adds

+uwsgi_param REQUEST_SCHEME  $scheme;
+uwsgi_param HTTPS           $https if_not_empty;

[wyardley]

Going to close this in favor of #855