meson-winbuild.sh: Disable ruledit build from installers other than qt5
Currently meson-winbuild.sh always builds ruledit. It should not build it for gtk3.22- or sdl2-client, only for qt5-client.
Currently meson-winbuild.sh always builds ruledit. It should not build it for gtk3.22- or sdl2-client, only for qt5-client.