prevent traceback. Fixes #4319

src/common/xmpp/client_nb.py

@@ -292,7 +292,8 @@ class NonBlockingClient(NBCommonClient):
 	def _on_auth_bind(self, data):
 		if data:
 			self.Dispatcher.ProcessNonBlocking(data)
-		if self.NonBlockingBind.bound is None: 
+		if not hasattr(self, NonBlockingBind) or self.NonBlockingBind.bound is \
+		None: 
 			return
 		self.NonBlockingBind.NonBlockingBind(self._Resource, self._on_sasl_auth)
 		return True
@@ -408,4 +409,4 @@ class Component(NBCommonClient):
 		self.NBComponentBind.PlugOut()
 		
 
-# vim: se ts=3:
\ No newline at end of file
+# vim: se ts=3: