PRESUBMIT.py, more helpful and stable error message for #include check.

Most problems are because of wrong collation or not reading the style guide, so
pointing people to those.

BUG=

Review URL: https://codereview.chromium.org/989533002

Cr-Commit-Position: refs/heads/master@{#319660}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 8bfd5cf..d631d4ffe 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -62,9 +62,9 @@
 
 
 _INCLUDE_ORDER_WARNING = (
-    'Your #include order seems to be broken. Send mail to\n'
-    '[email protected] if this is not the case.')
-
+    'Your #include order seems to be broken. Remember to use the right '
+    'collation (LC_COLLATE=C) and check https://google-styleguide.googlecode'
+    '.com/svn/trunk/cppguide.html#Names_and_Order_of_Includes')
 
 _BANNED_OBJC_FUNCTIONS = (
     (