Fix muc cert path

roles/prosody/templates/prosody.cfg.lua.j2

@@ -154,8 +154,8 @@ Component "conference.jabber.{{ domain }}" "muc"
     "vcard_muc";
   }
   ssl = {
-    key = "/etc/credentials/public/{{ domain }}/privkey.pem";
-    certificate = "/etc/credentials/public/{{ domain }}/fullchain.pem";
+    key = "/etc/credentials/public/conference.jabber.{{ domain }}/privkey.pem";
+    certificate = "/etc/credentials/public/conference.jabber.{{ domain }}/fullchain.pem";
   }
   max_history_messages = 500;
   muc_room_default_public = false;