fixed bug when supplying background
fixed bug when supplying background

AntonioJBT/CGATPipeline_core,AntonioJBT/CGATPipeline_core,AntonioJBT/CGATPipeline_core,CGATOxford/CGATPipelines,CGATOxford/CGATPipelines,CGATOxford/CGATPipelines,CGATOxford/CGATPipelines,CGATOxford/CGATPipelines,AntonioJBT/CGATPipeline_core