flutter_desktop: fix local cursor (hotx,hoty) offset

Signed-off-by: fufesou <shuanglongchen@yeah.net>

flutter/lib/desktop/pages/remote_page.dart

@@ -599,8 +599,8 @@ class ImagePaint extends StatelessWidget {
       return FlutterCustomMemoryImageCursor(
         pixbuf: cacheLinux.data,
         key: key,
-        hotx: cacheLinux.hotx,
-        hoty: cacheLinux.hoty,
+        hotx: 0.0,
+        hoty: 0.0,
         imageWidth: (cacheLinux.width * scale).toInt(),
         imageHeight: (cacheLinux.height * scale).toInt(),
       );

flutter/lib/models/model.dart

@@ -619,7 +619,7 @@ class CursorData {
   int _doubleToInt(double v) => (v * 10e6).round().toInt();
 
   String key(double scale) =>
-      '${peerId}_${id}_${_doubleToInt(hotx)}_${_doubleToInt(hoty)}_${_doubleToInt(width * scale)}_${_doubleToInt(height * scale)}';
+      '${peerId}_${id}_${_doubleToInt(width * scale)}_${_doubleToInt(height * scale)}';
 }
 
 class CursorModel with ChangeNotifier {