remove code block for ansible < 2.3

Old code, no need to support versions of
ansible under 2.3

Closed-Bug: #1860700
Change-Id: I26f65175b5013e8671a7c8e45389c8a82b668945

roles/libvirt/setup/undercloud/tasks/main.yml

@@ -349,27 +349,7 @@
     state: 'directory'
   when: non_root_chown|bool
 
-# This block only run when ansible version < 2.3.
-- block:
-    # Start the undercloud virtual machine.
-    - name: Start undercloud vm
-      virt:
-        name: "{{ undercloud_node.name }}"
-        command: start
-        state: running
-        uri: "{{ libvirt_uri }}"
-
-    # Configure the undercloud virtual machine to be
-    # automatically started at boot.
-    - name: Configure undercloud vm to start at virthost boot
-      virt:
-        name: "{{ undercloud_node.name }}"
-        command: autostart
-        uri: "{{ libvirt_uri }}"
-  when: ansible_version.full|version_compare('2.3','<')
-
 # Start the undercloud virtual machine and make it
-# automatically start for ansible-version >= 2.3
 - name: Start undercloud vm
   virt:
     name: "{{ undercloud_node.name }}"
@@ -377,7 +357,6 @@
     autostart: true
     state: running
     uri: "{{ libvirt_uri }}"
-  when: ansible_version.full|version_compare('2.3','>=')
 
 # Get the ip address of the undercloud.  This will retry several times
 # (`undercloud_ip_retries`) until the undercloud is ready.  The script