Fix centos qdrouterd for centos > 7
Fix centos qdrouterd for centos > 7

Yum doesn't present in centos/rhel version 8, we'll need to
use dnf in that case.

Change-Id: I2ccbfe4ae55c6a3653d8c03a12e6bca64e58d396
Closes-Bug: #1851135

stackforge/kolla,rahulunair/kolla,openstack/kolla,stackforge/kolla,stackforge/kolla,rahulunair/kolla,openstack/kolla