Hardcoded dupeGuru → se2.9

From GS

Moving files whilst Dupeguru music edition is scanning causes false matches. Eg: If doing housecleaning using explorer whilst the initial metadata is being scanned by Dupeguru ME, when Dupeguru gets to the comparing files stage, it incorrectly identifies the moved files as all being 0 bytes - and therefore lists all of the files in the "duplicates found" window - even though they are (a) not duplicates of each other and (b) not present in that location anyway.

This occurred using the audio content matching mode, haven't tested using the other modes.

Whilst this issue is due to a user messing about with file/folder locations during scanning (and so is really the user's fault), in my case the initial metadata scan of 70,000 files took quite a while - so I was trying to do other things at the same time. Now obviously, since the files do not exist in those locations any more, using select all and move to trash on the duplicate results won't cause any data loss of the moved files. However, it may cause user confusion and mean they no longer trust the authenticity of the scanner results, due to the mis-identification of duplicates.

Proposed resolution: In the content scan, always exclude 0 bytes files. Also, when grouping files at the end, exclude any match with a file that doesn't exist.