trydiff: extract 'date2' variable like existing 'date1' Note that there is a comment saying "ctx2 date may be dynamic". The comment was introduced in dccb83241dd0 (patch: use contexts for diff, 2006-12-25), but it seems like it stopped being dynamic in that very changeset -- before that changeset, the date seems to have been the file's mtime, but after the changeset, it seems to be the changeset's timestamp (current time for workingctx). Since no one seems to have missed the "dynamicness", let's simplify and extract a date2 for symmetry with date1.