t5551: compare sorted cookies files

t5551: compare sorted cookies files

In t5551 we check that we save cookies correctly to a file when
http.cookiefile and http.savecookies are set.  To do so we create an
expect file that expects the cookies in a certain order.

However after e2ef8d6fa ("cookies: support creation-time attribute for
cookies", 2018-08-28) in curl.git (released in curl 7.61.1) that order
changed.

We document the file format as "Netscape/Mozilla cookie file
format (see curl(1))", so any format produced by libcurl should be
fine here.  Sort the files, to be agnostic to the order of the
cookies, and make the test pass with both curl versions > 7.61.1 and
earlier curl versions.

Reported-by: Todd Zullinger <tmz@pobox.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>