The value in question is coming directly from `gnutls-serv`, so it cannot
be modified freely.
Reported-by: Marcel Raad
Ref: 6ae6b2a533 (commitcomment-30621004)
Otherwise, LF line endings are converted to CRLF on Windows,
but no conversion is done for the reply, so the test case fails.
Closes https://github.com/curl/curl/pull/2776
Also, make the ftp server return a canned response that doesn't
cause XML verification problems. Although the test file format
isn't technically XML, it's still handy to be able to use XML
tools to verify and manipulate them.