extension checker matches wrong types

Hi

It seems that the extension checker in mp3-scanner.c/scan_path() matches also files with an ending like bla.m or bla.mp.

The code checks if the file has more than 4 chars (true for x.mp3 but also for bla.m) and then checks if the extension (in this case .mp3 and .m) also appears in the list of allowed extensions. Which is true also in both cases.

Maybe you should additionally check if the extension is at least 3 chars long.

Denis