installer_cross: Let user to define MOCCMD
Make winbuild.sh to use MOCCMD from the environment, if it's already set there. This can be handy with the Qt6 build, don't think it's needed with Qt5 -> not targeting to S3_0 where only Qt5 is supported.
Make winbuild.sh to use MOCCMD from the environment, if it's already set there. This can be handy with the Qt6 build, don't think it's needed with Qt5 -> not targeting to S3_0 where only Qt5 is supported.