Remote desktop on Windows: say to choose Connect on mstsc's file prompt

Seen on Windows 11: an unsigned .rdp file makes mstsc ask about the
publisher before the certificate warning. Plain '>' in the message, which
a cp1252 console can print.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tests/test_rdp.py

@@ -66,6 +66,7 @@ class OpenRdp(unittest.TestCase):
         self.assertIn("steamos", message)
         self.assertIn("Developer Mode password", message)
         self.assertIn("certificate", message)
+        self.assertIn("Connect", message)
 
     def test_nothing_listening_says_why_and_opens_nothing(self):
         self.xrdp.close()