none shadow around checkbox

src/client/styles/scss/_override-bootstrap-variables.scss

@@ -106,5 +106,4 @@ $progress-box-shadow: none;
 
 //== Custom Checkbox
 $custom-checkbox-indicator-border-radius: 0px;
-$custom-checkbox-indicator-indeterminate-box-shadow: none;
-$custom-control-indicator-box-shadow: none;
+$custom-control-indicator-focus-box-shadow: none;