Fix TLS cert updates for kosmos.chat

Some recipes weren't updated for the proxy validation yet. Needed to
split the ejabberd cert in two, so it can do normal validation on
`.org` and proxy validation on `.chat`.

site-cookbooks/kosmos-hubot/recipes/nginx_botka_irc-libera-chat.rb

@@ -4,6 +4,7 @@ upstream_host = search(:node, "role:hubot").first["knife_zero"]["host"]
 
 tls_cert_for domain do
   auth "gandi_dns"
+  acme_domain "letsencrypt.kosmos.org"
   action :create
 end
 

site-cookbooks/kosmos-hubot/recipes/nginx_hal8000_xmpp.rb

@@ -5,6 +5,7 @@ upstream_host = search(:node, "role:hubot").first["knife_zero"]["host"]
 
 tls_cert_for domain do
   auth "gandi_dns"
+  acme_domain "letsencrypt.kosmos.org"
   action :create
 end