[gnome-photos] theme: Remove unused colour

[Debarshi Ray <debarshir src gnome org>]

commit 31fbf0dc3f5ecf852b65aed4e44ef5c46972bee9
Author: Debarshi Ray <debarshir gnome org>
Date:   Fri Jan 11 12:18:38 2019 +0100

    theme: Remove unused colour
    
    Fallout from 6699b53fdcbb0f69269626a078e3e33f34a250c6

 data/Adwaita.css | 2 --
 1 file changed, 2 deletions(-)
---
diff --git a/data/Adwaita.css b/data/Adwaita.css
index 0aeebb2d..a4882d87 100644
--- a/data/Adwaita.css
+++ b/data/Adwaita.css
@@ -1,6 +1,4 @@
 @define-color theme_base_color #333333;
-@define-color theme_bg_color #393f3f;
-
 @define-color photos_collection_bg #000000;
 
 GdMainIconView.content-view {