if there is an ephemeral hook the relay is never mute.

fixes https://github.com/fiatjaf/khatru/pull/53

handlers.go

@@ -240,7 +240,7 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 
 							// the number of notified listeners matters in ephemeral events
 							if nostr.IsEphemeralKind(env.Event.Kind) {
-								if n == 0 {
+								if n == 0 && len(rl.OnEphemeralEvent) == 0 {
 									ok = false
 									reason = "mute: no one was listening for this"
 								} else {