When the key is pressed update fullsreen flag

When the fullscreen client is running in the window manager using the server decoration (SSD), when the user performs fullscreen through the server decoration, the fullscreen flag is not synchronized, resulting in that the fullscreen flag of the fullscreen client is not updated, and the function of clicking fullscreen for the first time after using the server decoration to complete fullscreen is invalid. In order to solve this problem, I am working in fullscreen Button in C_ Add window to the handler interface_ is_ The fullscreen interface updates the fullscreen flag.