[PATCH 3 of 4] acl: mark deprecated config option

[Matt Mackall]

# HG changeset patch
# User Matt Mackall <mpm at selenic.com>
# Date 1435271806 18000
#      Thu Jun 25 17:36:46 2015 -0500
# Node ID 1a35d7bce493030b5a799f3408b150d9aa015216
# Parent  8908ef1715644db25d3d05aa8848e1bebd17e3b2
acl: mark deprecated config option

This option has been undocumented since day 0.

diff -r 8908ef171564 -r 1a35d7bce493 hgext/acl.py
--- a/hgext/acl.py	Thu Jun 25 17:35:57 2015 -0500
+++ b/hgext/acl.py	Thu Jun 25 17:36:46 2015 -0500
@@ -286,6 +286,7 @@
 
     ui.debug('acl: checking access for user "%s"\n' % user)
 
+    # deprecated config: acl.config
     cfg = ui.config('acl', 'config')
     if cfg:
         ui.readconfig(cfg, sections=['acl.groups', 'acl.allow.branches',