The BasicIndexingJob started from the UnindexedFileIndexer only has
the file extension based mimetype and thus can not determine if a file
should be indexed.
Remove the document only from the indexingleveldb, otherwise the
document can not be found e.g. by name or type, and the basic indexer is
run on the file again on each session start.
This is typical for e.g. xml files, which may come with various file
extensions based on the application, e.g. XMP sidecar files.