KERNEL-7542 优化设计器发现的一些问题

designer-base/src/main/java/com/fr/design/mainframe/EastRegionContainerPane.java

@@ -837,8 +837,10 @@ public class EastRegionContainerPane extends UIEastResizableContainer {
         }
 
         public void replaceContentPane(JComponent pane) {
-            contentArea.remove(this.contentPane);
+            if (pane != this.contentPane) {
-            contentArea.add(this.contentPane = pane);
+                contentArea.remove(this.contentPane);
+                contentArea.add(this.contentPane = pane);
+            }
             if (popupDialog != null && isPoppedOut) {
                 popupDialog.replaceContentPane(this);
             }