git-contacts: do not fail parsing of good diffs

If a line in a patch starts with "--- " it will be deemed
malformed unless it also contains the proper diff header
format. This situation can happen with a valid patch if
it has a line starting with "-- " and that line is removed.

This patch just removes the check in git-contacts.

Signed-off-by: Lars Gullik Bjønnes <larsbj@gullik.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/contacts/git-contacts

@@ -96,8 +96,6 @@ sub scan_patches {
 		next unless $id;
 		if (m{^--- (?:a/(.+)|/dev/null)$}) {
 			$source = $1;
-		} elsif (/^--- /) {
-			die "Cannot parse hunk source: $_\n";
 		} elsif (/^@@ -(\d+)(?:,(\d+))?/ && $source) {
 			my $len = defined($2) ? $2 : 1;
 			push @{$sources->{$source}{$id}}, [$1, $len] if $len;