fix trailing nulls in the ID3 strings
fix trailing nulls in the ID3 strings

this is caused by a bug in id3-go, it does not
remove the trailing nulls

somewhat addressed in https://github.com/mikkyang/id3-go/pull/8,
but the pull request does not fix all cases, like
removing null from any TextFrame, like the TCON
category
frodeaa/dircast