[FIX] base: correct m2o design for active items.

addons/web/static/src/css/base.css

@@ -2863,7 +2863,7 @@ div.ui-widget-overlay {
 }
 .ui-menu .ui-state-focus, .ui-menu .ui-state-active {
   background: #7c7bad !important;
-  border: 0 !important;
+  border: 1px solid #7c7bad !important;
 }
 .ui-menu .ui-state-focus a, .ui-menu .ui-state-active a {
   color: #ffffff !important;

addons/web/static/src/css/base.sass

@@ -2348,7 +2348,7 @@ div.ui-widget-overlay
             @include radius(0)
     .ui-state-focus, .ui-state-active
         background: #7c7bad !important
-        border: 0 !important
+        border: 1px solid #7c7bad !important
         a
             color: #ffffff !important
             font-weight: normal !important