K7ZipFileEntry: remove purposeless export macro from private class
Added with unmaintained/kdelibs@0318024b but given this was added to a source file and not otherwise used, seems rather a copy & paste error than planned goal to export symbols.
Added with unmaintained/kdelibs@0318024b but given this was added to a source file and not otherwise used, seems rather a copy & paste error than planned goal to export symbols.