Use specific imports in purge.py

Mostly this is an excuse to run the MSI CI tests.

Author: zware

Tools/msi/purge.py

@@ -10,7 +10,7 @@
 import re
 import sys
 
-from urllib.request import *
+from urllib.request import Request, urlopen
 
 VERSION_RE = re.compile(r'(\d+\.\d+\.\d+)([A-Za-z_]+\d+)?$')