patch 7.4.1247

Problem:    The channel test doesn't run on MS-Windows.
Solution:   Make it work on the MS-Windows console. (Ken Takata)

src/testdir/test_channel.py

@@ -7,12 +7,6 @@
 # Then Vim can send requests to the server:
 #  :let response = ch_sendexpr(handle, 'hello!')
 #
-# And you can control Vim by typing a JSON message here, e.g.:
-#   ["ex","echo 'hi there'"]
-#
-# There is no prompt, just type a line and press Enter.
-# To exit cleanly type "quit<Enter>".
-#
 # See ":help channel-demo" in Vim.
 #
 # This requires Python 2.6 or later.