Fixing problems installing IPFire on systems without randomness

This is a small patchset trying to fix problems with setting up IPFire on systems like PC Engines APU boards.

When running through setup, the admin password cannot be set because htpasswd(8) now calls the get_random() syscall which locks for forever when the kernel's CPRNG has not been initialised, yet.

These patches start rngd before that and pause the boot process until enough randomness is available.

This is not a great solution, but a good hotfix right now.

We will have to revisit this soon and hopefully get rid of the loopy script which has its own flaws.

I am happy to listen to any creative ideas :)

Best, -Michael