kconfig_compiler: delete the assignment operator and copy constructor

Summary:
of the generated class that has a pointer and raw copy would be bad.

Those generated classes are internal and nobody would probably have this, but being safe never hurts

Reviewers: vkrause

Reviewed By: vkrause

Subscribers: kde-frameworks-devel

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D18136