This update for dhcp fixes several issues.

This security issue was fixed:

- CVE-2017-3144: OMAPI code didn't free socket descriptors when empty message
is received allowing DoS (bsc#1076119).

These non-security issues were fixed:

- Optimized if and when DNS client context and ports are initted (bsc#1073935)
- Relax permission of dhclient-script for libguestfs (bsc#987170)
- Modify dhclient-script to handle static route updates (bsc#1023415).
- Use only the 12 least significant bits of an inbound packet's TCI value as the VLAN ID
to fix some packages being wrongly discarded by the Linux packet filter. (bsc#1059061)

This update was imported from the SUSE:SLE-12-SP1:Update update project.