Make lock on plasmavault icon visible with breeze-dark
Summary: Set lock color on Breeze version to #eff0f1 (light2dark script compatibility) and the lock on the Breeze Dark version to #31363b.
Reviewers: VDG, ngraham
Reviewed By: VDG, ngraham
Subscribers: ngraham, abetts, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D15721