Check docker subnet is same with neutron subnet when kuryr use existed neutron network

[Liping Mao]

When user create kuryr network with existed neutron network, if he assign subnet range not same with neutron subnet.
we get the following error message:
Error response from daemon: NetworkDriver.CreateNetwork: Subnets hosted on the same network must be allocated from the same subnet pool.
Neutron server returns request_ids: ['req-9d364ebf-6fba-4984-93eb-ce158ceb0042']

But the kuryr.net.uuid.lh and kuryr.net.uuid.uh tag on neutron network is still leave there.

example:
+---------------------------+----------------------------------------------------+
| Field | Value |
+---------------------------+----------------------------------------------------+
| admin_state_up | True |
| availability_zone_hints | |
| availability_zones | nova |
| created_at | 2016-12-02T04:08:27 |
| description | |
| id | 5b231d26-edd8-4536-90e6-be446530b86e |
| ipv4_address_scope | |
| ipv6_address_scope | |
| mtu | 1500 |
| name | provider-880 |
| port_security_enabled | True |
| provider:network_type | vlan |
| provider:physical_network | physnet1 |
| provider:segmentation_id | 880 |
| qos_policy_id | |
| router:external | False |
| shared | True |
| status | ACTIVE |
| subnets | 3ed277c0-48d5-4a79-8b9c-9bbaa9de6e75 |
| tags | kuryr.net.uuid.lh:df610e2b5fb937661f448627fe1c2761 |
| | kuryr.net.uuid.lh:ec998539b93feec5a6a0bbce47f876ff |
| | kuryr.net.uuid.lh:992cba477c02923705dfb1be5ff3297a |
| | kuryr.net.existing |
| | kuryr.net.uuid.uh:893920626fdee1956183405c1a1634ec |
| | kuryr.net.uuid.uh:c96305f1141a21a447b01986fe165fed |
| | kuryr.net.uuid.lh:de4e13b0839ca070058a7eac9cfeaa84 |
| | kuryr.net.uuid.uh:5b71a0a9c564d3e97450fc916d585cd9 |
| | kuryr.net.uuid.lh:abeb253c40faff2b2bf2cf0d44e24bf2 |
| | kuryr.net.uuid.uh:f4a6ed341fbff2817280df8370709bbf |
| | kuryr.net.uuid.uh:53bf6bbab7f8a371789b6d5c2a37d099 |
| | kuryr.net.uuid.lh:aa098d6d82547a1a255b2ff804235449 |
| | kuryr.net.uuid.uh:f3c68d33326315ce5ce8ae524823bc9f |
| tenant_id | 0da303c4058e4389918e684e2d36aaf4 |
| updated_at | 2016-12-02T04:08:27 |
+---------------------------+----------------------------------------------------+

This is because when user did not assign network uuid or network name, in vm nested case

[Liping Mao (limao)]

This bug will also impact vm nest case, when user create a kuryr network. vm-nested driver will choose the network of the vm by default if end user did not assign neutron network uuid or name, then it will go into this bug also.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Liping Mao (<email address hidden>) on branch: master
Review: https://review.openstack.org/413542