gitlab-ci and readme need to be updated

In a subrequest, the http_connection field is NULL.

Issue #28

In particulare the one in certs shows concrete examples on how to
generate VOMS proxies

The proxies had a wrong VO in the FQANs and couldn't be validated any
more by the VOMS lib. See commit
https://github.com/italiangrid/voms/commit/feeaed

encoding.t was also affected, but didn't require any change, just a
correctly generated proxy.

Apparently the bug mentioned in the (removed) comment has been fixed.
But this showed a bug in our test: http vs HTTP in the pattern to match
in the log.

Issue #17

Note that This test is always successful because, for some reason
(a bug?) the error.log as seen in Test::Nginx doesn't contain the
entries for the master process, although they are evailable in
the actual file. As a consequence the no_error_log check is
always satisfied, even if the segmentation fault were present

And related test.

fix issue #19