incorrect mime-type for AAC files on Windows

Icecast on Windows sends the wrong mime-type to a client for AAC-files. It is sending "application/octet-stream" in stead of "audio/aac" or "audio/aacp". this occurs only with files, live streams encoded by an AAC(+) encoder is being handled correctly. The reason for this is probably that icecast searches for mime-types on the wrong place.

The result is that players that expect the audio/aac(p) mime-type for AAC-files, do not play AAC-files served by icecast.