Update ironmq.rst

Changed Rackspace DFW endpoint to ORD. (ORD is newest IronMQ installation for Rackspace; DFW is being deprecated.)

docs/getting-started/brokers/ironmq.rst

@@ -48,9 +48,9 @@ And in this case the broker url may only be::
 Clouds
 ------
 
-The default cloud/region is ``AWS us-east-1``. You can choose the IronMQ Rackspace cloud by changing the URL to::
+The default cloud/region is ``AWS us-east-1``. You can choose the IronMQ Rackspace (ORD) cloud by changing the URL to::
 
-    ironmq://project_id:token@mq-rackspace-dfw.iron.io
+    ironmq://project_id:token@mq-rackspace-ord.iron.io
 
 Results
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