Fix and re-enable test_disassociate_not_associated_floating_ip

Fixes test_disassociate_not_associated_floating_ip so it sets the
ec2_client class variable needed by a base class correctly. There
has been some bit-rot since it was disabled.

Note that this test will not pass until the nova fix
https://review.openstack.org/#/c/124320/ has merged.

Change-Id: Ice39358f4e8123334f24056daede68bead59729b
Related-Bug: 1179816
diff --git a/tempest/thirdparty/boto/test_ec2_network.py b/tempest/thirdparty/boto/test_ec2_network.py
index a75fb7b..132a5a8 100644
--- a/tempest/thirdparty/boto/test_ec2_network.py
+++ b/tempest/thirdparty/boto/test_ec2_network.py
@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from tempest import test
 from tempest.thirdparty.boto import test as boto_test
 
 
@@ -22,21 +21,22 @@
     @classmethod
     def resource_setup(cls):
         super(EC2NetworkTest, cls).resource_setup()
-        cls.client = cls.os.ec2api_client
+        cls.ec2_client = cls.os.ec2api_client
 
     # Note(afazekas): these tests for things duable without an instance
-    @test.skip_because(bug="1080406")
     def test_disassociate_not_associated_floating_ip(self):
         # EC2 disassociate not associated floating ip
         ec2_codes = self.ec2_error_code
-        address = self.client.allocate_address()
+        address = self.ec2_client.allocate_address()
         public_ip = address.public_ip
-        rcuk = self.addResourceCleanUp(self.client.release_address, public_ip)
-        addresses_get = self.client.get_all_addresses(addresses=(public_ip,))
+        rcuk = self.addResourceCleanUp(self.ec2_client.release_address,
+                                       public_ip)
+        addresses_get = self.ec2_client.get_all_addresses(
+            addresses=(public_ip,))
         self.assertEqual(len(addresses_get), 1)
         self.assertEqual(addresses_get[0].public_ip, public_ip)
         self.assertBotoError(ec2_codes.client.InvalidAssociationID.NotFound,
                              address.disassociate)
-        self.client.release_address(public_ip)
-        self.cancelResourceCleanUp(rcuk)
+        self.ec2_client.release_address(public_ip)
         self.assertAddressReleasedWait(address)
+        self.cancelResourceCleanUp(rcuk)