MW 1.22 and SMW 1.9beta install/upgrade

I completely messed up things with MW 1.21.x and the "ExtensionInstaller" extension. Apparently or luckily this approach works as expected, too. This should also work for MW 1.19.x and 1.20.x

[[kgh]] (talk)

I need to remember documenting this too

[[kgh]] (talk)