opensound: add a safe source
opensound: add a safe source

Since it is not an official one, also keep a link to the git repo.

moochris/haikuports,miqlas/haikuports,miqlas/haikuports,moochris/haikuports,moochris/haikuports,koletzky/haikuports,haikuports/haikuports,nielx/haikuports,nielx/haikuports,haikuports/haikuports,Begasus/haikuports,Begasus/haikuports,Begasus/haikuports,Begasus/haikuports,haikuports/haikuports,nielx/haikuports,koletzky/haikuports,Begasus/haikuports,haikuports/haikuports,koletzky/haikuports,miqlas/haikuports,haikuports/haikuports