Fix button background color

When introducing night mode the rule for the background of the view 
switches seems to be generated from the view button.

This patch should change the introduced rule to fix for all default 
buttons.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

public/css/index.css

@@ -385,7 +385,7 @@ div[contenteditable]:empty:not(:focus):before{
     color: #eee;
 }
 
-.night .btn.btn-default.ui-view.active{
+.night .btn.btn-default.active{
     background: #202020;
 }