changegroup: don't try to prune manifest nodes if not ellipses In non-ellipses case, the number of manifest nodes can be very big, and finding whether one of them can be pruned or not is very costly. For each node, we try to find the rev and the linkrev, which is expensive. Sending bit more manifest nodes seems better and much faster here. On our internal repository, this saves around 5 seconds on `hg tracked --addinclude <some_path>` on a narrow repo with ellipses disabled. Differential Revision: https://phab.mercurial-scm.org/D5782