Update for new version of RMG-Py.
Update for new version of RMG-Py.

Currently works (or at least doesn't crash)
with ae9ce5916d28c609c0a41846bcf99d33e169e326
nickvandewiele/RMG-Py,chatelak/RMG-Py,nyee/RMG-Py,faribas/RMG-Py,KEHANG/RMG-Py,pierrelb/RMG-Py,comocheng/RMG-Py,comocheng/RMG-Py,nickvandewiele/RMG-Py,pierrelb/RMG-Py,faribas/RMG-Py,enochd/RMG-Py,chatelak/RMG-Py,KEHANG/RMG-Py,enochd/RMG-Py,nyee/RMG-Py