[gnome-chess] Fix another translator comment

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 021f3ec246dc56f443e3036c8e564f475794b273
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Wed Apr 9 19:30:31 2014 -0500

    Fix another translator comment

 data/preferences.ui |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/data/preferences.ui b/data/preferences.ui
index 1c4a8f5..0b8138b 100644
--- a/data/preferences.ui
+++ b/data/preferences.ui
@@ -239,7 +239,7 @@
                     <property name="visible">True</property>
                     <property name="can_focus">False</property>
                     <property name="xalign">0</property>
-                    <property name="label" translatable="yes" comments="Preferences Dialog: Label before 
promotion type combo box">_Difficulty:</property>
+                    <property name="label" translatable="yes" comments="Preferences Dialog: Label before 
difficulty level combo box">_Difficulty:</property>
                     <property name="use_underline">True</property>
                     <property name="mnemonic_widget">difficulty_combo</property>
                   </object>