client: register the global early, in pw_client_new()

otherwise, if the access module blocks the client, the on_start
callback in the protocol is not called and there is no global,
which means the session manager cannot do anything to grant
permissions on this client and the client is blocked forever

src/modules/module-protocol-native.c

@@ -308,9 +308,6 @@ static void on_start(void *data, uint32_t version)
 	if (version == 0)
 		client->compat_v2 = &this->compat_v2;
 
-	if (pw_client_register(client, NULL) < 0)
-		return;
-
 	return;
 }