Fix Python 3 KeyError 

pywikibot global option 'verbose' causes an exception on Python 3.

Replace algorithm with simpler approach that removes only pywikibot
sub-modules like 'wikipedia_family' from the package list.

Change-Id: Ic93b75b7b9e74a66ce3907fa4526e58d694492a5
Merge "Fix Python 3 KeyError "