[baloo_file] Wait for extractor process to start
Summary: When running baloo_file I hit the assert in extractorprocess.cpp:63. This was because the extractor process was not yet running when index was called. This could be observerd by connecting to the QProcess::started signal. Let's wait for the process to start before doing the indexing
Test Plan:
Before: run baloo_file -> assert
After: run baloo_file -> no assert, balooctl monitor shows that files are indexed
Reviewers: Baloo, bruns
Reviewed By: Baloo, bruns
Subscribers: bruns, apol, kde-frameworks-devel
Tags: Frameworks, Baloo
Differential Revision: https://phabricator.kde.org/D20940