Use the proper pod subnet instead the services one

Fixes #4809 ?

roles/flannel_register/defaults/main.yaml

@@ -1,7 +1,6 @@
 ---
-flannel_network: "{{ openshift.common.portal_net | default('172.30.0.0/16', true) }}"
-flannel_min_network: 172.30.5.0
-flannel_subnet_len: 24
+flannel_network: "{{ openshift.master.sdn_cluster_network_cidr }}"
+flannel_subnet_len: "{{ 32 - openshift.master.sdn_host_subnet_length }}"
 flannel_etcd_key: /openshift.com/network
 etcd_hosts: "{{ etcd_urls }}"
 etcd_conf_dir: "{{ openshift.common.config_base }}/master"

roles/flannel_register/templates/flannel-config.json

@@ -1,7 +1,6 @@
 {
     "Network": "{{ flannel_network }}",
     "SubnetLen": {{ flannel_subnet_len }},
-    "SubnetMin": "{{ flannel_min_network }}",
     "Backend": {
         "Type": "host-gw"
      }