vcfcluster reporting LEN=0 for all variants

[RCollins13]

Continued from a discussion from Slack.

I'm encountering an issue where standardized Manta VCFs aren't able to be clustered by vcfcluster, and instead each SV-sample pair is being reported as single record in the output clustered vcf with LEN=0.

I've moved two example input VCFs to ERISOne here:
/scratch/miket/rlc47temp/vcfcluster_debug/