[gtk/wip/matthiasc/popup5] Revert "Adwaita: Give popover menus a background"

[Matthias Clasen <matthiasc src gnome org>]

commit 59356fb7936b1cc3e4024e4dabcc0214e800a594
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun May 5 23:53:02 2019 +0000

    Revert "Adwaita: Give popover menus a background"
    
    This reverts commit eba3ee508e7951caf6a08fc108bfc41a1e2961da.

 gtk/theme/Adwaita/_common.scss | 4 ----
 1 file changed, 4 deletions(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index aab793d707..1faadd14a3 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -4700,7 +4700,3 @@ popover.emoji-completion contents row box {
 popover.emoji-completion .emoji:hover {
   background-color: $popover_hover_color;
 }
-
-popover.menu {
-  background-color: lightgray;
-}