While updating the address-scope with optional argument - -share=true, then user unable to update as - -share=false.

[Arundhati Surpur]

Problem:
While updating the address-scope with optional argument - -share=true, then user unable to update as - -share=false.

Steps to reproduce:

1) Update the address scope using the command
neutron address-scope-update --shared true 0055ebc1-771f-4f98-9775-bafd8f563061
2) Then try to update the address scope again
neutron address-scope-update --shared false 0055ebc1-771f-4f98-9775-bafd8f563061
output:
Unable to update address scope 0055ebc1-771f-4f98-9775-bafd8f563061 : Shared address scope can't be unshared.
Neutron server returns request_ids: ['req-d98ce885-7e18-4b1b-9d7b-2c7538f80156']

So, it should update the address scope as false again.

[Gary Kotton (garyk)]

This is currently by design - http://git.openstack.org/cgit/openstack/neutron/tree/neutron/db/address_scope_db.py#n88