[gtk+] Adwaita: remove unneeded margin on dropdown menu

[Lapo Calamandrei <lapo src gnome org>]

commit af76e138f947d5cf3e83e4b820f7e64fd0316799
Author: Lapo Calamandrei <calamandrei gmail com>
Date:   Tue May 9 12:45:22 2017 +0200

    Adwaita: remove unneeded margin on dropdown menu
    
    That margin was probably a left over to workaround some placement
    issue on dropdowns which doesn't exist anymore.

 gtk/theme/Adwaita/_common.scss |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index d971ac7..d2d9122 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -1898,7 +1898,6 @@ menubar,
 menu,
 .menu,
 .context-menu {
-  margin: 4px;
   padding: 2px 0px;
   background-color: $menu_color;
   border: 1px solid $borders_color; // adds borders in a non composited env