Fix handling of VMware cursors

This is a regression from ad0f061. If a VMware cursor rect was split up
over multiple read()s then the stream would become corrupted as we set
the restore point at the wrong place.

common/rfb/CMsgReader.cxx

@@ -636,11 +636,11 @@ bool CMsgReader::readSetVMwareCursor(int width, int height, const Point& hotspot
   if (!is->hasData(1 + 1))
     return false;
 
+  is->setRestorePoint();
+
   type = is->readU8();
   is->skip(1);
 
-  is->setRestorePoint();
-
   if (type == 0) {
     int len = width * height * (handler->server.pf().bpp/8);
     rdr::U8Array andMask(len);