【fix】【大纲】删除大纲所在页面，大纲列表该大纲会显示成0页，此时右键编辑该大纲，必现崩溃

PDF Office/PDF Master/Class/PDFWindowController/Side/LeftSide/KMLeftSideViewController+Outline.swift

@@ -713,9 +713,12 @@ extension KMLeftSideViewController {
     //弹出菜单
     
     @objc func outlineContextMenuItemClicked_Edit(_ sender: AnyObject?) {
+        let ol: CPDFOutline? = self.tocOutlineView.km.clickedItem()
+        guard let _ = ol?.km_page else {
+            return
+        }
         let popover = NSPopover()
         popover.delegate = self
-        let ol: CPDFOutline? = self.tocOutlineView.km.clickedItem()
         let vc = KMOutlineEditViewController(outline: ol, document: self.listView)
         if let cell = self.tocOutlineView.rowView(atRow: self.tocOutlineView.clickedRow, makeIfNecessary: true) {
             popover.contentViewController = vc