Don't use a verified nullptr as a data source

Summary:
Actually use some variables with usable information in version.h

Don't de-reference what will at this point definitely be a null ptr

Also use the information from version.h to perform the same task,
now that that information is, in fact, useful

Reviewers: Frameworks, KNewStuff, Plasma, ronaldv, apol

Reviewed By: apol

Subscribers: kde-frameworks-devel

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D25922