test-http-bad-server: move on test from bytes-count to pattern
This specific test case is now using the new "close when a pattern is seen"
approach compared to the more fragile "that many bytes were sent" approach.
Since such change are still a bit noisy, we split each change in there own
changesets.
Differential Revision: https://phab.mercurial-scm.org/D12060
edition = "2018"
max_width = 79
wrap_comments = true
error_on_line_overflow = true