engine: Remove warning about using default namespace
engine: Remove warning about using default namespace

The warning is scary for users as most users don't need to explicitly
specify a namespace, and can run in the default namespace.

kklin/kelda,PenguinToast/quilt,ejj/quilt-dev,mmussomele/quilt,mmussomele/quilt,kklin/quilt,quilt/quilt,mmussomele/quilt,NetSys/quilt,NetSys/quilt,mmussomele/quilt,tejasmanohar/quilt,kelda/kelda,PenguinToast/quilt,quilt/quilt,LuiseV/quilt,ejj/quilt-dev,stevenlin598/quilt,kayousterhout/quilt,PenguinToast/quilt,kayousterhout/quilt,kklin/quilt,tejasmanohar/quilt,kayousterhout/quilt,stevenlin598/quilt,LuiseV/quilt,kklin/kelda,kelda/kelda,PenguinToast/quilt,stevenlin598/quilt,LuiseV/quilt,kklin/quilt,tejasmanohar/quilt,LuiseV/quilt,NetSys/quilt,tejasmanohar/quilt,LuiseV/quilt,kayousterhout/quilt,ejj/quilt-dev,ejj/quilt-dev,kelda/kelda,mmussomele/quilt,stevenlin598/quilt,kklin/quilt,NetSys/quilt,mmussomele/quilt,kklin/kelda,NetSys/quilt,kelda/kelda,quilt/quilt,kklin/kelda,PenguinToast/quilt,stevenlin598/quilt,quilt/quilt,stevenlin598/quilt