Trim last indent guide

Summary: Changelog: UIDebugger: Reimplemented Tree, inline attributes, faster performance and added indent guides

Reviewed By: lblasa

Differential Revision: D42031069

fbshipit-source-id: f1394ca528005e645760ea38cb5c4c805d122a4b

desktop/plugins/public/ui-debugger/components/Tree.tsx

@@ -486,6 +486,12 @@ function toTreeNodes(
     }
   }
 
+  //always trim last indent guide
+  const prevItemLine = last(treeNodes)?.indentGuide;
+  if (prevItemLine != null) {
+    prevItemLine.trimBottom = true;
+  }
+
   return treeNodes;
 }