Remove unused variable (#6522)

roles/kubernetes/master/defaults/main/main.yml

@@ -26,9 +26,6 @@ kube_apiserver_node_port_range: "30000-32767"
 # ETCD backend for k8s data
 kube_apiserver_storage_backend: etcd3
 
-# By default, force back to etcd2. Set to true to force etcd3 (experimental!)
-force_etcd3: false
-
 kube_etcd_cacert_file: ca.pem
 kube_etcd_cert_file: node-{{ inventory_hostname }}.pem
 kube_etcd_key_file: node-{{ inventory_hostname }}-key.pem
@@ -166,9 +163,6 @@ kube_encryption_algorithm: "aescbc"
 # Which kubernetes resources to encrypt
 kube_encryption_resources: [secrets]
 
-# You may want to use ca.pem depending on your situation
-kube_front_proxy_ca: "front-proxy-ca.pem"
-
 # If non-empty, will use this string as identification instead of the actual hostname
 kube_override_hostname: >-
   {%- if cloud_provider is defined and cloud_provider in [ 'aws' ] -%}