Fix ID3v2 padding size calculation.
Fix ID3v2 padding size calculation.

videolabs/taglib,dlz1123/taglib,TsudaKageyu/taglib,pbhd/taglib,pbhd/taglib,MaxLeb/taglib,dlz1123/taglib,black78/taglib,dlz1123/taglib,taglib/taglib,MaxLeb/taglib,pbhd/taglib,Distrotech/taglib,TsudaKageyu/taglib,i80and/taglib,davispuh/taglib,black78/taglib,davispuh/taglib,i80and/taglib,black78/taglib,i80and/taglib,taglib/taglib,videolabs/taglib,davispuh/taglib,videolabs/taglib,Distrotech/taglib,TsudaKageyu/taglib,Distrotech/taglib,MaxLeb/taglib,taglib/taglib