Accept LF terminated headers

[mbr]

While it seems that CRLF line-endings are the only ones acceptable by the standard, just LF line-endings often end up being used as well (e.g. using nc to test and forgetting the -C parameter).

Using a sole \n as the header terminator results in rouille just being stuck (probably waiting for the first line to end), which is very confusing when debugging. Could/should we add the recommended "tolerance" for these kinds of line endings?

[kolbma]

This is in https://github.com/kolbma/tiny-http/commits/dev-20240117/