Fix etc/hosts format with baremetal role

While is not an issue, just an style format,
etc/hosts generated by baremetal role have
some tabs where it shouldn't.

Change-Id: I90d82ea78b3dac7e8ec3f8cc546b67cc61c41536
Closes-Bug: #1692913

ansible/roles/baremetal/tasks/pre-install.yml

@@ -23,7 +23,7 @@
     block: |
         {% for host in groups['all'] %}
         {{ hostvars[host]['ansible_' + hostvars[host]['api_interface']]['ipv4']['address'] }} {{ hostvars[host]['ansible_hostname'] }}
-          {% endfor %}
+        {% endfor %}
   become: True
   when: customize_etc_hosts | bool