THRIFT-5757: align Python cross-test launchers
diff --git a/test/py/TestServer.py b/test/py/TestServer.py
index dcc46d7..59a06ad 100755
--- a/test/py/TestServer.py
+++ b/test/py/TestServer.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+#!/usr/bin/env python
 
 #
 # Licensed to the Apache Software Foundation (ASF) under one