THRIFT-3798 THttpClient does not use proxy from http_proxy, https_proxy environment variables

Fix CI failure due to PEP8 violation

This closes #1097
diff --git a/lib/py/src/transport/THttpClient.py b/lib/py/src/transport/THttpClient.py
index a492789..fb33421 100644
--- a/lib/py/src/transport/THttpClient.py
+++ b/lib/py/src/transport/THttpClient.py
@@ -105,7 +105,7 @@
             self.__http = http_client.HTTPSConnection(self.host, self.port)
             if self.using_proxy():
                 self.__http.set_tunnel(self.realhost, self.realport,
-                                       { "Proxy-Authorization": self.proxy_auth })
+                                       {"Proxy-Authorization": self.proxy_auth})
 
     def close(self):
         self.__http.close()