Skip validation of MACS config when it is not set
Skip validation of MACS config when it is not set

ewels/NGI-ChIPseq,chuan-wang/NGI-ChIPseq,chuan-wang/NGI-ChIPseq,chuan-wang/NGI-ChIPseq,ewels/NGI-ChIPseq,ewels/NGI-ChIPseq,ewels/NGI-ChIPseq,ewels/NGI-ChIPseq,chuan-wang/NGI-ChIPseq