search-editor: Fix operator border-radius in filter-editor in Safari

Author: flourish86

asset/css/search-editor.less

@@ -20,12 +20,12 @@
 
   select:not([multiple]) {
     .appearance(none);
-    border-radius: 0;
     padding-right: 1.5625em;
     background-image: url('@{iplWebAssets}/img/select-icon-text-color.svg');
     background-repeat: no-repeat;
     background-position: right center;
     background-size: contain;
+    .rounded-corners(0);
   }
 
   i.icon:before {