#1340 option "-sharerect WxH+L+T" doesn't update screen

[mafo]

Using the command line option "-sharerect WIDTHxHEIGHT+LEFT+TOP" (with different parameters for LEFT and TOP and Full HD for WIDTH and HEIGHT, for example) on a running controlapp instance doesn't mostly update the screen. Therefore, VNC-Viewer on Client must be restarted each time in order to refresh the whole screen.