convert shebang lines: python -> python3
diff --git a/Tools/scripts/nm2def.py b/Tools/scripts/nm2def.py
index 9dfb991..8f07559 100755
--- a/Tools/scripts/nm2def.py
+++ b/Tools/scripts/nm2def.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 """nm2def.py
 
 Helpers to extract symbols from Unix libs and auto-generate