Replace non-ascii with ascii (#7044)

When opening the main.yaml, vi cannot show the string correctly
due to non-ascii string. This replaces it.

roles/kubespray-defaults/defaults/main.yaml

@@ -382,7 +382,7 @@ external_openstack_network_public_networks:
 authorization_modes: ['Node', 'RBAC']
 rbac_enabled: "{{ 'RBAC' in authorization_modes }}"
 
-# When enabled, API bearer tokens (including service account tokens) can be used to authenticate to the kubelet’s HTTPS endpoint
+# When enabled, API bearer tokens (including service account tokens) can be used to authenticate to the kubelet's HTTPS endpoint
 kubelet_authentication_token_webhook: true
 
 # When enabled, access to the kubelet API requires authorization by delegation to the API server