Ensure that when we request firmware info nothing else is in the queue
Depending on how the machine was disconnected and what the client does after disconnect there could be items in the queue to be sent before
our M115 command. This will make sure our m115 is sent first by clearing the cache.
Reviewers: tcanabrava, laysrodrigues, patrickelectric
Reviewed By: patrickelectric
Subscribers: Atelier: AtCore
Tags: Atelier: AtCore
Differential Revision: https://phabricator.kde.org/D18349