Allow for a key to be deployed on all hosts

To use a key as backup key to be deployed on all hosts.

roles/archusers/templates/authorized_keys.j2

@@ -2,7 +2,7 @@
 {{ lookup('file', '../pubkeys/' + item.value.ssh_key) }}
 {% if item.value.additional_ssh_keys is defined %}
 	{% for key in item.value.additional_ssh_keys %}
-		{% if inventory_hostname in key.hosts %}
+		{% if inventory_hostname in key.hosts or 'all' in key.hosts %}
 {{ lookup('file', '../pubkeys/' + key.name) }}
 		{% endif %}
 	{% endfor %}