Beam: disable parallel builds.
Beam: disable parallel builds.

They don't work reliably because of missing dependencies on generated .h
files.

moochris/haikuports,haikuports/haikuports,moochris/haikuports,haikuports/haikuports,Begasus/haikuports,Begasus/haikuports,nielx/haikuports,moochris/haikuports,haikuports/haikuports,haikuports/haikuports,nielx/haikuports,Begasus/haikuports,nielx/haikuports,haikuports/haikuports,Begasus/haikuports,Begasus/haikuports