test-http-bad-server: document that the value are actually a list I don't really expect this doc to be read a lot, but mentioning that this is a list seems important. Differential Revision: https://phab.mercurial-scm.org/D12048

test-http-bad-server: refactor the writing logic to avoid early return Our ultimate goal is to add another way to define the connection needs to be closed. To do so, we need the "read" code to be more unified. Differential Revision: https://phab.mercurial-scm.org/D12047

test-http-bad-server: replace the default 65537 value in output This is the default block value that we use here and it make the output overall less readable. So we replace it with `~` Differential Revision: https://phab.mercurial-scm.org/D12046