Fix code up

Author: emlynmac

articles/communication-services/quickstarts/chat/includes/meeting-interop-javascript.md

@@ -199,7 +199,7 @@ var chatThreadId = "";
 
 async function init() {
   const connectionString = "<SECRET_CONNECTION_STRING>";
-  const endpointUrl = connectionString.split(";")[0];
+  const endpointUrl = connectionString.split(";")[0].replace("endpoint=", "");
 
   const identityClient = new CommunicationIdentityClient(connectionString);