Don't consider balanced valid for has_payout_route

gratipay/models/participant.py

@@ -773,7 +773,7 @@ def get_cryptocoin_addresses(self):
 
     @property
     def has_payout_route(self):
-        for network in ('balanced-ba', 'paypal'):
+        for network in ('paypal',):
             route = ExchangeRoute.from_network(self, network)
             if route and not route.error:
                 return True