Reparse configuration before (un)loading scripts

When the scripting KCM triggered a loading of a script it did not work
because the scripting code was operating on an old data set.

Reparsing the configuration before evaluating which scripts to (un)load
solves this problem.

Cherry-picked from 4.10 branch: dd5b4bdec8e24359d4715c078e2f442967a3f873