color: update the help with the new default
The default is now "auto" we update the help to match reality.
--- a/mercurial/help/config.txt Wed Apr 12 16:48:13 2017 +0200
+++ b/mercurial/help/config.txt Mon Apr 17 20:22:00 2017 +0200
@@ -1863,7 +1863,7 @@
``color``
String: when to use to colorize output. possible value are auto, always,
- never, or debug (default: never). 'auto' will use color whenever it seems
+ never, or debug (default: auto). 'auto' will use color whenever it seems
possible. See :hg:`help color` for details.
(in addition a boolean can be used in place always/never)