[PATCH 2 of 2] help: correct a typo in tweakdefaults

[Matt Harbison]

# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1536108881 14400
#      Tue Sep 04 20:54:41 2018 -0400
# Node ID 197521083166579f6c80d7532ec6e919af2fe2cf
# Parent  ae1442742d796285b85bf9e0e0159665414f0478
help: correct a typo in tweakdefaults

diff --git a/mercurial/help/config.txt b/mercurial/help/config.txt
--- a/mercurial/help/config.txt
+++ b/mercurial/help/config.txt
@@ -2354,7 +2354,7 @@ User interface controls.
     to release, but over time the recommended config settings
     shift. Enable this config to opt in to get automatic tweaks to
     Mercurial's behavior over time. This config setting will have no
-    effet if ``HGPLAIN` is set or ``HGPLAINEXCEPT`` is set and does
+    effect if ``HGPLAIN` is set or ``HGPLAINEXCEPT`` is set and does
     not include ``tweakdefaults``. (default: False)
 
 ``username``