Bug 1013064 - Pushing the first commit to an empty git repo results in Git fatal error

Based on reported bug: https://bugzilla.redhat.com/show_bug.cgi?id=1013064

Updating the check for the branch in the openshift app repo. If the return value of the `git ls-tree...` is unsuccessful and returns value > 0 ( no branch is present ), the output is redirected to 2/dev/null, and no hot deploy is needed.

Also when the app is created with empty repo  and no initial (or other commits) are present, no hot deploy is needed.