Pass Proxy() timeout parameter properly

Previously setting the timeout would never work as the super() call used
HTTP_TIMEOUT instead.

 [ yapified by gitreformat (github/ghtdak) on Mon Nov 30 21:11:13 2015 ]

Author: petertodd

bitcoin/rpc.py

@@ -220,7 +220,7 @@ def __init__(self,
         super(Proxy, self).__init__(service_url=service_url,
                                     service_port=service_port,
                                     btc_conf_file=btc_conf_file,
-                                    timeout=HTTP_TIMEOUT,
+                                    timeout=timeout,
                                     **kwargs)
 
     def getaccountaddress(self, account=None):