Fix hostmanger ip resolver exception when guest is not really up
Fix hostmanger ip resolver exception when guest is not really up

The bug is discussed here:
https://github.com/smdahlen/vagrant-hostmanager/issues/121
so use the suggested workaround in ip resolver to catch the error.

Change-Id: Ibac510ca9aef57b508036266987b136d95771074

unibg-seclab/devstack-vagrant,meniy/Devstack-Vagrant,verdurin/devstack-vagrant,meniy/Vagrant,AlessandroCopler/TestVagrant,AlessandroCopler/test_esc,openstack-dev/devstack-vagrant,nexusz99/devstack-vagrant,openstack-dev/devstack-vagrant,verdurin/devstack-vagrant,Sunnepah/devstack-vagrant,olivierlemasle/devstack-vagrant,meniy/Vagrant,j4/devstack-vagrant,meniy/Vagrant,meniy/Devstack-Vagrant,olivierlemasle/devstack-vagrant,unibg-seclab/devstack-vagrant,AlessandroCopler/test_esc,Sunnepah/devstack-vagrant,AlessandroCopler/TestVagrant,j4/devstack-vagrant,nexusz99/devstack-vagrant,unibg-seclab/devstack-vagrant