Feature #5630: Reproducible builds
Invalid MBR ID passed to isohybrid
Symptoms: #11983#note-7. Once I've made isohybrid more verbose I saw "isohybrid: invalid id: `'1490015021''". So passing
--id $SOURCE_DATE_EPOCH to isohybrid made the ISO reproducible… because it's an invalid ID and so we stopped hybriding the ISO.
Pass a fixed and valid ID to isohybrid's --id parameter (refs: #12453).
Due to a mistake I did wrt. shell quoting in
6fcb23230c782b878c66019e4101ad3ec8632f25, we were actually passing "--id
'1490015021'" (with the single quotes), which is an invalid ID. So isohybrid
was aborting. As a result isohybrid stopped creating non-reproducible ISOs,
but the resulting ISO images were not hybrid'ed.
Let's not bother passing $SOURCE_DATE_EPOCH, and just pass a fixed value.