Wrong return code for resolution change

[any1]

When a client request a resolution change, returning true from the callback results in RFB_RESIZE_STATUS_SUCCESS being sent over the wire.

It would be more accurate to return RFB_RESIZE_STATUS_REQUEST_FORWARDED because the resolution isn't actually changed until the frame buffer dimensions change and when that happens, the server sends a resize event to the client.

This does not seem to cause any issues, but it is a spec violation.