[gnome-mines] Use renamed gtk-icon-effect attribute

[Robert Roth <robertroth src gnome org>]

commit 8613fe8f28987edda2c930bee47fecd37a28807a
Author: Robert Roth <robert roth off gmail com>
Date:   Sat Mar 5 01:27:05 2016 +0200

    Use renamed gtk-icon-effect attribute

 data/gnome-mines.css |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/data/gnome-mines.css b/data/gnome-mines.css
index f84b65f..8fafc03 100644
--- a/data/gnome-mines.css
+++ b/data/gnome-mines.css
@@ -10,7 +10,7 @@
 }
 
 .count, .explodedField .tile {
--gtk-image-effect: none;
+-gtk-icon-effect: none;
 }
 
 .navigation {