Also enable shell runner for kicker

Summary: Kickoff has the shell runner enabled as part of "extraRunners" as well.

Test Plan: Typed in ls, can run ls now.

Reviewers: Plasma, hein

Reviewed By: Plasma, hein

Subscribers: ngraham, plasma-devel

Tags: Plasma

Differential Revision: https://phabricator.kde.org/D9093