convert shebang lines: python -> python3
diff --git a/Tools/scripts/objgraph.py b/Tools/scripts/objgraph.py
index 0975a3b..1e1fce0 100755
--- a/Tools/scripts/objgraph.py
+++ b/Tools/scripts/objgraph.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 # objgraph
 #