Same problem here. For info I also tried plain raspbian and openhab via packages (no openhabian) but expereince the same issue. As posted here:
Tried with a fresh SD flash and got this
Every 2.0s: cat /boot/first-boot.log openHABianPi: Fri Jan 11 14:48:52 2019
2018-03-13_22:53:37_UTC [openHABian] Starting the openHABian initial setup.
2018-03-13_22:53:37_UTC [openHABian] Storing configuration... OK
2018-03-13_22:53:37_UTC [openHABian] Changing default username and password... OK
2018-03-13_22:53:38_UTC [openHABian] Setting up Ethernet connection... OK
2018-03-13_22:53:38_UTC [openHABian] Ensuring network connectivity... OK
2018-03-13_22:53:38_UTC [openHABian] Waiting for dpkg/apt to get ready... OK
2019-01-11_14:46:53_UTC [openHABian] Updating repositories and upgrading installed packages... FAILED
2019-01-11_14:47:12_UTC [openHABian] Initial setup exiting with an error!
EDIT: After a reboot it seems to work better…but not running yet