Snippets for kup-backup 6.8.0 from Alpine s390x

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-s390x/community/kup/kup-6.8.0-r0.log.

• /home/buildozer/aports/community/kup/src/kup-6.8.0/daemon/backupjob.cpp:29:18: warning: ignoring return value of 'virtual bool QFile::open(QIODeviceBase::OpenMode)', declared with attribute 'nodiscard' [-Wunused-result]
     29 |     mLogFile.open(QIODevice::WriteOnly | QIODevice::Truncate);
        |     ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~