gitlab-ci and readme need to be updated

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