Unbreak module imports for Python2

Test Plan: Using kapidox_generate with python3 & python2 works

Reviewers: ochurlaud, cordlandwehr, davidedmundson

Reviewed By: davidedmundson

Subscribers: bcooksley, awilcox, kde-frameworks-devel, kde-doc-english

Tags: Frameworks, Documentation

Differential Revision: https://phabricator.kde.org/D26652