https-client was putting newlines at 256-byte boundaries

https-client was putting newlines at 256-byte boundaries

presumably this was meant to put a ">" before every line, but that
isn't what it does, since evbuffer_remove is simply returning
fixed-size chunks.  So, when retrieving a document of more than 256
bytes (e. g. any nontrivial document), we got "> " and newlines thrown
in at very arbitrary places.