Steps to reproduce:

1. create Mercurial repository hosted by Phabricator
2. clone it
3. enable Largefiles extension via ~/.hgrc
4. add large files via 'hg add --large files...' and commit
5. push to Phabricator's server

Expected result: repository is pushed, no errors.

Actual result: the error "remote: Exception: Unknown Mercurial command 'putlfile!abort: unexpected response: empty string" is appeared.