convert shebang lines: python -> python3
diff --git a/Lib/smtpd.py b/Lib/smtpd.py
index 3dc9793..17b7427 100755
--- a/Lib/smtpd.py
+++ b/Lib/smtpd.py
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 """An RFC 2821 smtp proxy.
 
 Usage: %(program)s [options] [localhost:localport [remotehost:remoteport]]