Remove checkFileExists()

[IJabz]

This file does exist as was found by code new FileIO but checkFileExists is incorrectly reporting false. Not sure why but I think best to just remove this check

java.io.FileNotFoundException: Unable to find:/Volumes/share/import_CD/Cheryl Studer  Plácido Domingo  Etc.  Giuseppe Sinopoli  Philharmonia Orchestra  Royal Opera House Chorus/Wagner  Tannhäuser [Disc 1]/04 Wagner  Tannhäuser - Act 1  Dir Töne Lob! Die Wunder Sei'N Gepriesen.flac
    at org.jaudiotagger.audio.AudioFileIO.checkFileExists(AudioFileIO.java:441)
    at org.jaudiotagger.audio.AudioFileIO.readFile(AudioFileIO.java:351)
    at org.jaudiotagger.audio.AudioFileIO.read(AudioFileIO.java:196)
    at com.jthink.songkong.db.SongCache.addSongToDatabase(SongCache.java:242)
    at com.jthink.songkong.fileloader.LoadFolderWorker.addSongsToDatabase(LoadFolderWorker.java:503)
    at com.jthink.songkong.fileloader.LoadFolderWorker.call(LoadFolderWorker.java:115)
    at com.jthink.songkong.fileloader.LoadFolderWorker.call(LoadFolderWorker.java:30)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:748)

[IJabz]

As this seems to sometimes falsely report non-existence, moved these up front checks to further down, only to be performed if there is an issue when actually attempt read.

[IJabz]

Fixed.