Change Openstack default floating IP quota from 50 to 10

Copied from slack conversation:

Encountered issue while creating a new router

Error: Quota exceeded for resource router. Details

No more IP addresses available on network acc19436-59c4-4bce-a4ab-a115be45ceb9. Neutron server returns request_ids: ['req-fb3b5874-b2f1-4956-af28-65c93a47ac27']

After @cmcclung released some Floating IPs, I was able to create a new router. This brings us back to this backlog item: packer-openstack-hpc-image#117 @cmcclung also pointed out that we might want to revisit the default quota setting for Floating IP. The quota for server is 10 while quota for Floating IP is 50.