adapt request-pull tests for new pull request format

adapt request-pull tests for new pull request format

10eb0007 (request-pull: avoid mentioning that the start point is a
single commit, 2010-01-29), changed the pull request format, so the
test needs some changes to still pass:

 - tolerate a missing blank line between “in the git repository at:”
   and the name of repository and branch

 - recognize subject and date in the new request format

 - update the expected request template to match the new format

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>