Pass Proxy() timeout parameter properly

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

Author: petertodd

bitcoin/rpc.py

@@ -209,7 +209,7 @@ def __init__(self, service_url=None,
         timeout - timeout in seconds before the HTTP interface times out
         """
         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):
         """Return the current Bitcoin address for receiving payments to this account."""