outgoing: fix possible filtering crash in outgoing (
issue3814)
If there is no outgoiing changesets but we have filtered revision in outgoing.excluded
We run into a filtering related crash. The excluded revision should not be there
in the first place but discovery need cleanup in default, not stable.
Testing that hghave does not crash when checking features
$ "$TESTDIR/hghave" --test-features 2>/dev/null