Reorder state check in hoomd.Simulation.run
Reorder state check in hoomd.Simulation.run

This prevents an AttributeError on a private (underscored) attribute of
`hoomd.Simulation`. It also keeps the error messages relevant.

joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue