Custom tag based on #AudioChannels

[simoncn]

MinimServer goes by what the FLAC file encoding says. To recognise these files as multichannel, you would need to encode them as multichannel in the FLAC file. Your other option is to leave these files as encoded as 2-channel and add an explicit MutliChannel tag to each file.

In either case, no change to the tag update file is needed.