qml: use same main-server icon as in desktop client

electrum/gui/qml/components/controls/ServerDelegate.qml

@@ -29,11 +29,12 @@ ItemDelegate {
         }
 
         Item {
-            Layout.preferredWidth: constants.iconSizeSmall
+            Layout.preferredWidth: constants.iconSizeMedium
-            Layout.preferredHeight: constants.iconSizeSmall
+            Layout.preferredHeight: constants.iconSizeMedium
-            Label {
+            Image {
-                text: '❤'
+                source: '../../../icons/chevron-right.png'
-                anchors.centerIn: parent
+                width: constants.iconSizeMedium
+                height: constants.iconSizeMedium
                 visible: model.is_primary
             }
         }