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.