The default redirection maximum for `curl` is 50 but we should use
something more reasonable in livecheck. It's rare but a misconfigured
server with an endless redirection loop will hit the 50 redirection
limit. Unfortunately, we've encountered this in the wild (e.g., the
server for `getmail` and `memtester` endlessly redirects), so it's
not an idle concern. This commit basically adds `--max-redirs 5` to
`Livecheck::Strategy::DEFAULT_CURL_ARGS` to enforce a more reasonable
redirection maximum.
To be clear, the `max_iterations` logic in `#parse_curl_output`
(which was previously found in `Strategy#page_content`) doesn't
restrict the number of redirections that `curl` follows. At the point
the `curl` output is being parsed, the requests have already been
made and `max_iterations` simply restricts the number of responses
`#parse_curl_output` is willing to parse. If we use `--max-redirs`
and properly set `max_iterations` to `max-redirs + 1`, we shouldn't
encounter the "Too many redirects" error in `#parse_curl_output`.