【打印】内容选择框-框选后，切换到其他app-回来，右键-点击打印，必现崩溃 -- 修复

PDF Office/PDF Master/Class/PDFTools/Print/KMPrintWindowController.swift

@@ -375,7 +375,7 @@ extension KMPrintWindowController {
             let controller = KMPrintAccessoryController_OC(nibName: "KMPrintAccessoryController_OC", bundle: nil)
             printOperation.printPanel.addAccessoryController(controller)
             
-            printOperation.runModal(for: NSApplication.shared.mainWindow!, delegate: self, didRun: nil, contextInfo: nil)
+            printOperation.runModal(for: NSWindow.currentWindow(), delegate: self, didRun: nil, contextInfo: nil)
         }
     }