Comment 51 for bug 1453738

I fixed/workarounded this by removing the cryptswap line from /etc/crypttab and instead adding swap to /etc/fstab (non-encrypted). Then I rebooted and the password prompt didn't come up anymore. This only started to come after I had some booting problems because I messed it up so I had to use boot-repair to get it to work somehow and fix the rest myself.

This might be considered unsafe, but it works for me and should be suitable for my needs.