dhcp/nettools: add siaddr to lease options

This is so that we end up with a next-server option analogous to what
dhclient helper sends us. Dracut uses this for networked boots.
18 jobs for lr/nettools-siaddr in 95 minutes and 50 seconds (queued for 17 seconds)
latest
Status Job ID Name Coverage
  Test
passed #964775
allowed to fail
checkpatch

00:01:05

manual #964781
allowed to fail manual
t_centos:7.5.1804
passed #964782
t_centos:7.6.1810

00:23:46

passed #964788
t_debian:10

00:17:24

passed #964787
t_debian:9

00:15:12

passed #964790
t_debian:sid

00:18:58

manual #964789
allowed to fail manual
t_debian:testing
manual #964776
allowed to fail manual
t_fedora:28
passed #964777
t_fedora:29

00:32:32

passed #964778
t_fedora:30

00:27:20

passed #964779
t_fedora:31

00:28:37

manual #964780
allowed to fail manual
t_fedora:rawhide
passed #964783
t_ubuntu:16.04

00:16:44

passed #964784
t_ubuntu:18.04

00:18:42

manual #964786
allowed to fail manual
t_ubuntu:devel
manual #964785
allowed to fail manual
t_ubuntu:rolling
 
  External
failed https://desktopqe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/beaker-NetworkManager-gitlab-trigger-code-upstream/884/

failed https://desktopqe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/beaker-NetworkManager-gitlab-trigger-code-upstream/884/

05:11:44