【综合】整理代码

PDF Office/PDF Master/Class/PDFTools/EditPDF/Tools/KMEditPDfHanddler.swift

@@ -1199,7 +1199,7 @@ extension KMEditPDfHanddler {
         }
         if areas.count == 1 {
             if KMTools.isPDFType(format) {
-                guard let image = areas.first!.thumbnailImage else {
+                guard let image = areas.first?.thumbnailImage else {
                     NSSound.beep()
                     return
                 }