[PATCH 2 of 2] configitems: fixup default value of diff config option

[Boris Feld]

# HG changeset patch
# User Boris Feld <boris.feld at octobus.net>
# Date 1507925335 -7200
#      Fri Oct 13 22:08:55 2017 +0200
# Node ID 596df3e78d9c2670f00ea3a0b9870b0fced57deb
# Parent  b3b1e118238d5897da17c41e66a1ce46ebc8096b
# EXP-Topic config.register.fixup
# Available At https://bitbucket.org/octobus/mercurial-devel/
#              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 596df3e78d9c
configitems: fixup default value of diff config option


It turned out that configbool is used for most of them so the registered
default value was wrong.

diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -248,34 +248,34 @@
     default=None,
 )
 coreconfigitem('diff', 'nodates',
-    default=None,
+    default=False,
 )
 coreconfigitem('diff', 'showfunc',
-    default=None,
+    default=False,
 )
 coreconfigitem('diff', 'unified',
     default=None,
 )
 coreconfigitem('diff', 'git',
-    default=None,
+    default=False,
 )
 coreconfigitem('diff', 'ignorews',
-    default=None,
+    default=False,
 )
 coreconfigitem('diff', 'ignorewsamount',
-    default=None,
+    default=False,
 )
 coreconfigitem('diff', 'ignoreblanklines',
-    default=None,
+    default=False,
 )
 coreconfigitem('diff', 'ignorewseol',
-    default=None,
+    default=False,
 )
 coreconfigitem('diff', 'nobinary',
-    default=None,
+    default=False,
 )
 coreconfigitem('diff', 'noprefix',
-    default=None,
+    default=False,
 )
 coreconfigitem('email', 'bcc',
     default=None,