gitweb: Fix error in git_patchset_body for deletion in merge commit

Checking if $diffinfo->{'status'} is equal 'D' is no longer the way to
check if the file was deleted in result.  For merge commits
$diffinfo->{'status'} is reference to array of statuses for each
parent.  Use the fact that $diffinfo->{'to_id'} is all zeros as sign
that file was deleted in result.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

gitweb/gitweb.perl

@@ -2722,8 +2722,9 @@ sub git_patchset_body {
 					delete $from{'href'};
 				}
 			}
+
 			$to{'file'} = $diffinfo->{'to_file'} || $diffinfo->{'file'};
-			if ($diffinfo->{'status'} ne "D") { # not deleted file
+			if ($diffinfo->{'to_id'} ne ('0' x 40)) { # file exists in result
 				$to{'href'} = href(action=>"blob", hash_base=>$hash,
 				                   hash=>$diffinfo->{'to_id'},
 				                   file_name=>$to{'file'});