retrieve omnibus.chef_version directly from global config
retrieve omnibus.chef_version directly from global config

This ensures we are dealing with the final, finalized version.

petems/vagrant-puppet-install,cregev/vagrant-puppet-install,srhopkins/vagrant-puppet-install,chef/vagrant-omnibus,srhopkins/vagrant-puppet-install,cregev/vagrant-puppet-install,petems/vagrant-puppet-install,cgvarela/vagrant-omnibus