Python PEP-8 conformity

Hello,

This fixes a 2-indent instead of the regular 4-indent spaces (tab4 macro) used everywhere else in the python code in function emitFunctionShadowHelper.
This fixes an error with doctest wanting pep8 indentation.


It'd be nice to `$(check_pep8)` here too - I think we still get a single python wrapper despite the multiple C++ files involved.