Initialize m_output_moment_inertia in HOOMDDumpWriter
Initialize m_output_moment_inertia in HOOMDDumpWriter

It wasn't being initialized leading to undefined behavior.
joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue,joaander/hoomd-blue