Per Martins request, add empty.vbs to Tools\msi\msi.py.

This file is used by test_startfile.py.

Tools/msi/msi.py

@@ -917,6 +917,7 @@ def add_files(db):
             lib.add_file("testtar.tar")
             lib.add_file("test_difflib_expect.html")
             lib.add_file("check_soundcard.vbs")
+            lib.add_file("empty.vbs")
             lib.glob("*.uue")
             lib.add_file("readme.txt", src="README")
         if dir=='decimaltestdata':