Elastic: Fix width of some select fields in sieve filter form

Not working properly since we use .custom-select without .form-control

skins/elastic/styles/widgets/forms.less

@@ -92,6 +92,7 @@ input.smart-upload {
     td.rowactions {
         width: 1%;
 
+        .custom-select,
         .form-control {
             width: auto;
         }