No-op SeachRunner if indexing is disabled
Summary: We won't have any results anyway.
Test Plan:
Disabled indexing and put a qDebug in the if branch
I'm not super convinced it's a good idea myself. It means parsing a config file every match
and it can't be cached without missing updates if the user enables/disables at runtime.
Reviewers: Plasma
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D2995