changegroup: use positive logic for treemanifest changegroup3 logic
We are about to add more cases, in that context, it is simpler to avoid double
negative.
En addition, We document the situation for the next soul.
Differential Revision: https://phab.mercurial-scm.org/D6938
fixbundle() {
grep -v 'saving bundle' | grep -v 'saved backup' | \
grep -v added | grep -v adding | \
grep -v "unable to find 'e' for patching" | \
grep -v "e: No such file or directory" | \
cat
}