Fix checkbox not being disabled per dropdown default

And tweak checkbox position.

interface/resources/qml/dialogs/CustomQueryDialog.qml

@@ -211,6 +211,7 @@ ModalWindow {
                     left: parent.left;
                     bottom: parent.bottom;
                     leftMargin: 6;  // Magic number to align with warning icon
+                    bottomMargin: 6;
                 }
             }
 
@@ -339,6 +340,7 @@ ModalWindow {
 
     Component.onCompleted: {
         updateIcon();
+        updateCheckbox();
         d.resize();
         textField.forceActiveFocus();
     }