gitweb: Handle commits with empty commit messages more reasonably

Currently those look very weird, you can't get easily at the commit view
etc. This patch makes their title '(no commit message)'.

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

gitweb/gitweb.perl

@@ -1071,6 +1071,9 @@ sub parse_commit {
 			last;
 		}
 	}
+	if ($co{'title'} eq "") {
+		$co{'title'} = $co{'title_short'} = '(no commit message)';
+	}
 	# remove added spaces
 	foreach my $line (@commit_lines) {
 		$line =~ s/^    //;