Fixed updateConfiguations call when pruning prep network
Fixed updateConfiguations call when pruning prep network

Discussed in #58. @jwallen made the change in 4ef7e32,
just missed this case.
nyee/RMG-Py,nickvandewiele/RMG-Py,pierrelb/RMG-Py,comocheng/RMG-Py,KEHANG/RMG-Py,enochd/RMG-Py,enochd/RMG-Py,chatelak/RMG-Py,faribas/RMG-Py,pierrelb/RMG-Py,faribas/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py,chatelak/RMG-Py,KEHANG/RMG-Py,comocheng/RMG-Py