Avoid error if DP is not in VCF file. #1339
Avoid error if DP is not in VCF file. #1339

Some callers won't have the DP in the final VCF,
then the variant_summary fails. Ignore all those cases
where "." is given, and only calculate quantiles if
there are numeric values in the colum.
Thanks to @lbeltrame.

mjafin/bcbio-nextgen,vladsaveliev/bcbio-nextgen,brainstorm/bcbio-nextgen,mjafin/bcbio-nextgen,lbeltrame/bcbio-nextgen,brainstorm/bcbio-nextgen,chapmanb/bcbio-nextgen,a113n/bcbio-nextgen,lbeltrame/bcbio-nextgen,biocyberman/bcbio-nextgen,brainstorm/bcbio-nextgen,biocyberman/bcbio-nextgen,lbeltrame/bcbio-nextgen,a113n/bcbio-nextgen,vladsaveliev/bcbio-nextgen,mjafin/bcbio-nextgen,a113n/bcbio-nextgen,biocyberman/bcbio-nextgen,chapmanb/bcbio-nextgen,chapmanb/bcbio-nextgen,vladsaveliev/bcbio-nextgen