patch 7.4.1291
Problem:    On MS-Windows the channel test server doesn't quit.
Solution:   Use return instead of break. (Ken Takata)
diff --git a/src/testdir/test_channel.py b/src/testdir/test_channel.py
index 40a2043..039a9de 100644
--- a/src/testdir/test_channel.py
+++ b/src/testdir/test_channel.py
@@ -133,7 +133,7 @@
                     elif decoded[1] == '!quit!':
                         # we're done
                         self.server.shutdown()
-                        break
+                        return
                     elif decoded[1] == '!crash!':
                         # Crash!
                         42 / 0