Change the flow control when loading families list.
Change the flow control when loading families list.

This is a small change, but it changes the indentation of 
a huge block of code so looks like a big one. 
pierrelb/RMG-Py,chatelak/RMG-Py,nyee/RMG-Py,nyee/RMG-Py,faribas/RMG-Py,comocheng/RMG-Py,comocheng/RMG-Py,enochd/RMG-Py,nickvandewiele/RMG-Py,enochd/RMG-Py,faribas/RMG-Py,chatelak/RMG-Py,pierrelb/RMG-Py,KEHANG/RMG-Py,KEHANG/RMG-Py,nickvandewiele/RMG-Py