[kcms/keys] Really ignore unknown action
Summary:
Otherwise the end() iterator is dereferenced resulting in a crash
BUG: 421016
Test Plan: Import a predefined scheme
Reviewers: ngraham, Plasma, mart
Reviewed By: ngraham, Plasma, mart
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D29579