fix cbz export

lib/utils/cbz.dart

@@ -187,7 +187,7 @@ abstract class CBZ {
       }
       int i = 1;
       for (var image in allImages) {
-        var src = File(image.replaceFirst('file://', ''));
+        var src = openFilePlatform(image);
         var width = allImages.length.toString().length;
         var dstName =
             '${i.toString().padLeft(width, '0')}.${image.split('.').last}';

lib/utils/io.dart

@@ -324,6 +324,9 @@ Directory openDirectoryPlatform(String path) {
 }
 
 File openFilePlatform(String path) {
+  if(path.startsWith("file://")) {
+    path = path.substring(7);
+  }
   if(App.isAndroid) {
     var f = AndroidFile.fromPathSync(path);
     if(f == null) {