Fix border placement in Dropdown control

Source/Engine/UI/GUI/Common/Dropdown.cs

@@ -489,12 +489,14 @@ namespace FlaxEngine.GUI
                 BorderColor = BorderColorHighlighted,
                 Width = 4.0f,
                 AnchorPreset = AnchorPresets.StretchAll,
+                Offsets = Margin.Zero,
                 Parent = popup,
             };
 
             var itemsHeight = 20.0f;
             var itemsMargin = 20.0f;
-            // Scale height and margive with text height if needed
+
+            // Scale height and margin with text height if needed
             var textHeight = Font.GetFont().Height;
             if (textHeight > itemsHeight)
             {
@@ -509,6 +511,7 @@ namespace FlaxEngine.GUI
                 itemsWidth = Mathf.Max(itemsWidth, itemsMargin + 4 + font.MeasureText(_items[i]).X);
             }
             */
+
             var itemsWidth = Width;
             var height = container.Margin.Height;