contrib/git-jump: fix greedy regex when matching hunks

contrib/git-jump: fix greedy regex when matching hunks

The hunk-header regex looks for "\+\d+" to find the
post-image line numbers, but it skips the pre-image line
numbers with a simple ".*". That means we may greedily eat
the post-image numbers and match a "\+\d" further on, in the
funcname text.

For example, commit 6b9c38e has this hunk header:

  diff --git a/t/t0006-date.sh b/t/t0006-date.sh
  [...]
  @@ -50,8 +50,8 @@ check_show iso-local "$TIME" '2016-06-15 14:13:20 +0000'

If you run:

  git checkout 6b9c38e
  git jump diff HEAD^ t/

it will erroneously match "+0000" as the starting line
number and jump there, rather than line 50.

We can fix it by just making the "skip" regex non-greedy,
taking the first "+" we see, which should be the post-image
line information.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>