Fix a division by zero error when parsing an APE file.
Fix a division by zero error when parsing an APE file.

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