Allow pushes without pushing LFS objects
### Summary
When pushing a repo with LFS without pushing LFS objects pre-commit hook fails.
### Steps to reproduce
* Create an empty repo.
* Add a file.
* Track it with LFS.
* Add it.
* Commit.
* Disable LFS in the repo.
* Push.
### What is the current *bug* behavior?
pre-receive hook declined
### What is the expected *correct* behavior?
The push should succeed because some clients have no support for LFS.
issue