Fix crash in MPI/constraint simulations
Fix crash in MPI/constraint simulations

now that the ghost layer width can change, CellList always
needs current values, otherwise m_dim will be != m_cell_indexer
and read accesses go out of bound

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