Need to clear previous state after a restart (Or just everytime we st…

…art) to prevent channel unbindings from occurring.

src/Bayeux/BayeuxClient.php

@@ -163,6 +163,7 @@ protected function createClient(string $version = "44.0")
 
     public function start()
     {
+        $this->previousStates = [];
         $this->setState(new State\HandshakeState($this, $this->logger));
         do {
             $this->state->handle();