[gnome-boxes] content-bg: Use theme color instead of image

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit b4a3531a53d0675b93c9a9b0ee9c1de8808a8386
Author: Lasse Schuirmann <lasse schuirmann gmail com>
Date:   Mon Aug 18 12:31:17 2014 +0200

    content-bg: Use theme color instead of image
    
    This is a minor visual change while it allows Boxes to adapt to theme
    changes and especially makes themes like the high contrast accessibility
    theme work.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=731952

 data/gnome-boxes.gresource.xml |    1 -
 data/gtk-style.css             |    3 +--
 data/icons/boxes-dark.png      |  Bin 6946 -> 0 bytes
 3 files changed, 1 insertions(+), 3 deletions(-)
---
diff --git a/data/gnome-boxes.gresource.xml b/data/gnome-boxes.gresource.xml
index 2d67f92..d190d57 100644
--- a/data/gnome-boxes.gresource.xml
+++ b/data/gnome-boxes.gresource.xml
@@ -4,7 +4,6 @@
     <file>gtk-style.css</file>
     <file>icons/boxes-arrow.svg</file>
     <file>icons/boxes-create.png</file>
-    <file>icons/boxes-dark.png</file>
     <file>icons/boxes-gray.png</file>
     <file preprocess="xml-stripblanks">ui/app-window.ui</file>
     <file preprocess="xml-stripblanks">ui/auth-notification.ui</file>
diff --git a/data/gtk-style.css b/data/gtk-style.css
index b573292..fc084d6 100644
--- a/data/gtk-style.css
+++ b/data/gtk-style.css
@@ -62,8 +62,7 @@ BoxesMiniGraph {
 }
 
 .content-bg {
-    background-image: url("icons/boxes-dark.png");
-    border-image-repeat: stretch;
+    background-color: @content_view_bg;
 }
 
 .boxes-wizard-label {