Fix error in the registration example.

The now=True parameter was not being passed to allow the registration
submission to be submitted while the send queue is paused.

examples/register_account.py

@@ -101,7 +101,7 @@ class RegisterBot(sleekxmpp.ClientXMPP):
         resp['register']['password'] = self.password
 
         try:
-            resp.send()
+            resp.send(now=True)
             logging.info("Account created for %s!" % self.boundjid)
         except IqError as e:
             logging.error("Could not register account: %s" %