This reverts commit 71d020735b.
Unfortunately there are still some cases where we need to set Hydra's
concurrency separately.  (Ideally, Hydra would start *all* queued
builds in parallel and let Nix take care of everything...)
		
	
This reverts commit 71d020735b.
Unfortunately there are still some cases where we need to set Hydra's
concurrency separately.  (Ideally, Hydra would start *all* queued
builds in parallel and let Nix take care of everything...)