convert shebang lines: python -> python3
diff --git a/Tools/scripts/reindent-rst.py b/Tools/scripts/reindent-rst.py
index 55b99eb..246af3e 100755
--- a/Tools/scripts/reindent-rst.py
+++ b/Tools/scripts/reindent-rst.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Make a reST file compliant to our pre-commit hook.
 # Currently just remove trailing whitespace.