【优化】禅道Crash问题修复

FX_OutOfMemoryTerminate(unsigned long)
https://appcenter.ms/users/support-pdfreaderpro.com/apps/PDF-Reader-Pro-DMG/crashes/errors/3024549572u/overview

PDF Office/PDF Master/Class/PDFWindowController/Side/LeftSide/Thumbnail/Base/KMPDFThumbViewBaseController.swift

@@ -808,7 +808,7 @@ class KMPDFThumbViewBaseController: KMBaseViewController {
         
         var newIndexs = IndexSet()
         for i in indexs {
-            if let _ = self.thumbnailView.document?.page(at: UInt(i)).copy() as? CPDFPage {
+            if let _ = self.thumbnailView.document?.page(at: UInt(i)) as? CPDFPage {
                 newIndexs.insert(i)
             }
         }