Linux build compiles against csound development branch, causing breaking change

[cdelston0]

Hi,

I have been compiling Cabbage on a RPi 4 8GB, and getting build errors preventing successful build.
I tracked this down to the build.py script cloning the csound master branch. They're now working on 7.x releases there.
Windows and MacOS builds specifically use versions of csound from the 6.x series.
I replaced the git clone with an wget of the 6.18.x release and it allowed Cabbage to build successfully.

Thanks,

Chris.

[forrcaho]

This should be fixed with the PR I just submitted #156