Fix functional test_server tests
Fix functional test_server tests

Now oslo.service 0.10.0 no longer sends SIGHUP to parent and
children services.

This was a chance introduced by 286a6ea, and since it invalidated
the very logic under test, this must be revised.

Change-Id: I18a11283925369bc918002477774f196010a1bc3
Closes-bug: #1505438

klmitch/neutron,chitr/neutron,eayunstack/neutron,bigswitch/neutron,yanheven/neutron,openstack/neutron,mahak/neutron,chitr/neutron,MaximNevrov/neutron,sebrandon1/neutron,openstack/neutron,bigswitch/neutron,huntxu/neutron,klmitch/neutron,cloudbase/neutron,dims/neutron,apporc/neutron,apporc/neutron,wolverineav/neutron,MaximNevrov/neutron,dims/neutron,asgard-lab/neutron,asgard-lab/neutron,glove747/liberty-neutron,glove747/liberty-neutron,jumpojoy/neutron,eayunstack/neutron,igor-toga/local-snat,noironetworks/neutron,igor-toga/local-snat,cloudbase/neutron,openstack/neutron,huntxu/neutron,noironetworks/neutron,wolverineav/neutron,jumpojoy/neutron,yanheven/neutron,mahak/neutron,sebrandon1/neutron,mahak/neutron