Add IP as hostname for proxy mode

templates/ssh_config.jinja2

@@ -14,6 +14,9 @@ Host {{ hostname }}{% for alias in host.aliases|default([]) %} {{ alias }}{% end
 {% endfor %}
 {% endif %}
 {% if host.proxy is defined %}
+{% if host.ip is defined %}
+  Hostname {{ host.ip }}
+{% endif %}
   ForwardAgent yes
   ProxyCommand /usr/bin/ssh {{ host.proxy }} /bin/nc %h %p
 {% endif %}