`01-basic/G-compile-flags`:missing `cmake-gui` picture

[syheliel]

in https://github.com/ttroy50/cmake-examples/tree/master/01-basic/G-compile-flags:
the picture link(https://github.com/ttroy50/cmake-examples/blob/master/01-basic/G-compile-flags/cmake-gui-set-cxx-flag.png) is not available