[Baloo] Fix firstRun and config change logic
Summary:
FirstRun should only be set if baloo was *never ever* run before, and
this case is already handled by baloo internally.
Do no try to do a baloo config refresh if it has just been quit.
Also avoid triggering a config update immediately after starting baloo,
it will do another walk of the directory tree.
Reviewers: Baloo, ngraham, Plasma
Reviewed By: Baloo, ngraham
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D27917