Don't update MSYS2/MINGW packages per default at "ridk install"
Don't update MSYS2/MINGW packages per default at "ridk install"

That way the package versions of the build time are installed per default and not the latest one.
Updating to the latest package versions can cause compatibility issues with the installed older ruby build.

Fixes #168

oneclick/rubyinstaller2,oneclick/rubyinstaller2,oneclick/rubyinstaller2