Thrift-1784: pep-3110 exception handling
Client: py
Patch: jfarrell

Updates python lib for pep-3110
diff --git a/lib/py/src/server/THttpServer.py b/lib/py/src/server/THttpServer.py
index be54bab..6f92173 100644
--- a/lib/py/src/server/THttpServer.py
+++ b/lib/py/src/server/THttpServer.py
@@ -73,7 +73,7 @@
         oprot = thttpserver.outputProtocolFactory.getProtocol(otrans)
         try:
           thttpserver.processor.process(iprot, oprot)
-        except ResponseException, exn:
+        except ResponseException as exn:
           exn.handler(self)
         else:
           self.send_response(200)