Fix: direct s2s connection not always possible

Trying to connect to a remote instance using direct s2s won't work if local instance has not the feature enabled, and if the remote instance does not know the local one.
So using Websocket S2S in such case (that embed a discovery mecanism).

server/lib/prosody/config/content.ts

@@ -302,6 +302,12 @@ class ProsodyConfigContent {
     // FIXME: seems to be necessary to add the module on the muc host, so that dialback can trigger route/remote.
     this.muc.add('modules_enabled', 'websocket_s2s_peertubelivechat')
 
+    // Using direct S2S for outgoing connection can be an issue, if the local instance dont allow incomming S2S.
+    // Indeed, the remote instance will not necessarely be able to discover the Websocket Endpoint.
+    // To be sure the remote instance knows the websocket endpoint, we must use Websocket for the firt outgoing connect.
+    // So, we will add a parameter for mod_s2s_peertubelivechat, to tell him not to use outgoint s2s connection.
+    this.global.set('s2s_peertubelivechat_no_outgoing_directs2s_to_peertube', s2sPort === null)
+
     this.muc.add('modules_enabled', 'dialback') // This allows s2s connections without certicicates!
     this.authenticated?.add('modules_enabled', 'dialback') // This allows s2s connections without certicicates!
   }