updated the installer design

browser-qt/design/design.qss.in

@@ -98,6 +98,10 @@ QPushButton:pressed {
 */
 }
 
+QListView::indicator {
+    border: 2px solid white;
+}
+
 QRadioButton::indicator,
 QTreeView::indicator,
 QCheckBox::indicator {
@@ -105,7 +109,7 @@ QCheckBox::indicator {
     border-radius: 4px;
 }
 
-QRadioButton::indicator:checked,
+QListView::indicator:checked,
 QTreeView::indicator:checked,
 QCheckBox::indicator:checked {
     background-color: #771091;