Making sure to capture the rect returned by the remote tree branch

Otherwise the scrollable area will be restrcticted to the local branch
tree

Author: StanleyGoldman

src/UnityExtension/Assets/Editor/GitHub.Unity/UI/BranchesView.cs

@@ -316,7 +316,7 @@ private void OnTreeGUI(Rect rect)
 
             rect.y += Styles.TreePadding;
 
-            treeRemotes.Render(rect, scroll, _ => {}, selectedNode =>
+            rect = treeRemotes.Render(rect, scroll, _ => {}, selectedNode =>
                 {
                     var indexOfFirstSlash = selectedNode.Name.IndexOf('/');
                     var originName = selectedNode.Name.Substring(0, indexOfFirstSlash);