Avoid non-recognizing the label type on operation load at operation controller

Before this we were getting a tags instead of branches when $label->type was set as (string) VERSIONCONTROL_LABEL_BRANCH.

For example try lo load something like this(with othe values), using a hash of a commit that is on a branch and see its labels:

$c = new VersioncontrolGitOperationController();
$commit_ids = array('0f0280aefe4d0c3384cb04a0bbb15c9543f46a69');
$b = new VersioncontrolGitBackend;
$repository = $b->loadEntity('repo',array(9));
$commits = $repository->loadCommits(array(), array('revision' => $commit_ids), array('may cache' => FALSE));
dsm($commits);