Description of problem:
Booting of PXE less discovery image is failing with network initialization error, because of slow DHCP network.

How reproducible:
On customers side.

Steps to Reproduce:
1. create a discovery image
2. boot the server
3. wait for error

Actual results:
Boot fails with network initialization error.

Expected results:
Discovery image will boot.

Additional info:
Adding sleep(15) at the top of the configure_network function workarounds the issue. According to lzap we should include delay feature to PXE less initialization, same as we have in PXE initialization.