Description of problem:
openflow won't be updated after changing dnsName in egressnetworkpolicy, and egressnetwork is not working with the new dnsName


Version-Release number of selected component (if applicable):
openshift v3.6.49
kubernetes v1.5.2+43a9be4
openvswitch-2.6.1-10.git20161206.el7fdp.x86_64


How reproducible:
4/5


Steps to Reproduce:
1. Create a project
oc new-project pro1
2. Create a egressnetworkpolicy by admin
oc create -f policy.json
{
    "kind": "EgressNetworkPolicy",
    "apiVersion": "v1",
    "metadata": {
        "name": "policy2"
    },
    "spec": {
        "egress": [
            {
                "type": "Allow",
                "to": {
                    "dnsName": "www.google.com"
                }
            },
            {
                "type": "Deny",
                "to": {
                     "dnsName": "www.cisco.com"
                }
            }
        ]
    }
}

3. Check the openflow on node
 cookie=0x0, duration=19.897s, table=100, n_packets=0, n_bytes=0, priority=2,ip,reg0=0xe27851,nw_dst=172.217.5.228 actions=output:2
 cookie=0x0, duration=19.882s, table=100, n_packets=0, n_bytes=0, priority=1,ip,reg0=0xe27851,nw_dst=23.214.121.109 actions=drop

4. Change the dnsName in the egressnetworkpolicy
eg: 
                "type": "Allow",
                "to": {
                    "dnsName": "www.baidu.com"
                }
            },
            {
                "type": "Deny",
                "to": {
                     "dnsName": "www.yahoo.com"
5. Wait a few minutes (more than 10 minutes) and check the openflow again
6. Delete the egressnetworkpolicy
# oc delete egressnetworkpolicy policy2
egressnetworkpolicy "policy2" deleted
7. Wait more than 30minutes, and check the openflow again

Actual results:
step5: openflow won't be updated after changing dnsName in egressnetworkpolicy
 cookie=0x0, duration=142.554s, table=100, n_packets=0, n_bytes=0, priority=2,ip,reg0=0xe27851,nw_dst=172.217.5.228 actions=output:2
 cookie=0x0, duration=142.539s, table=100, n_packets=0, n_bytes=0, priority=1,ip,reg0=0xe27851,nw_dst=23.214.121.109 actions=drop

step7: openflow still exist even the egressnetworkpolicy have been deleted.
 cookie=0x0, duration=2313.637s, table=100, n_packets=0, n_bytes=0, priority=2,ip,reg0=0xe27851,nw_dst=172.217.5.228 actions=output:2
 cookie=0x0, duration=2313.622s, table=100, n_packets=0, n_bytes=0, priority=1,ip,reg0=0xe27851,nw_dst=23.214.121.109 actions=drop


Expected results:
openflow will be updated according to the dnsName change


Additional info:
1. openflow could be updated after changing cidrSelector in egressnetworkpolicy
2. old openflow could be updated/deleted after restating openvswitch