tracker-extract-mp3: Do not always use guessed encoding for ID3v2
tracker-extract-mp3: Do not always use guessed encoding for ID3v2

Always using guessed 8-bit encoding for ID3v2 breaks some valid MP3
files. This commit disables use of guessed encoding for ID3v2 except
for Cyrillic locales where broken ID3v2 tags appear to be common.

Fixes NB#278171.

hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker