Add error msg for check of local ip (#6761)

When stopping at the check of "Stop if ip var does not match local ips"
the error message is like:

  fatal: [single-k8s]: FAILED! => {
      "assertion": "ip in ansible_all_ipv4_addresses",
      "changed": false,
      "evaluated_to": false,
      "msg": "Assertion failed"
  }

That doesn't contain actual IP addresses and it is difficult to understand
what was wrong. This adds the error message which contain actual IP addresses
to investigate the issue if happens.

roles/kubernetes/preinstall/tasks/0020-verify-settings.yml

@@ -95,6 +95,7 @@
 - name: Stop if ip var does not match local ips
   assert:
     that: ip in ansible_all_ipv4_addresses
+    msg: "'{{ ansible_all_ipv4_addresses }}' do not contain '{{ ip }}'"
   when:
     - not ignore_assert_errors
     - ip is defined