THRIFT-1773. Revert "Thrift-1604:Python exxception handeling for changes from PEP3110"

This reverts commit 6c5ee6ad2067e245ab5364f9a6019d8b63d7ed52.

This commit is being reverted since it broke compatibility with
Python 2.4, which is the latest version included in RHEL5 releases.
diff --git a/lib/py/src/server/THttpServer.py b/lib/py/src/server/THttpServer.py
index 6f92173..be54bab 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 as exn:
+        except ResponseException, exn:
           exn.handler(self)
         else:
           self.send_response(200)