Race condition while booting systemd with zfs-root

I solved a long annoying boot-problem happened in the systemd-async-boot-process.

Adding a sleeptime in /lib/systemd/system/systemd-udev-settle.service by adding ExecStartPre=/usr/bin/sleep 5 to the [Service]-Section, gives the system 5 sec. more time to load the zfs-module and import the pool before it tries to remount root to the real directory on disk.