Fix issue with zero-padding in sv names

[mwohl]

Tested this fix using both the minimal test set and the NGS16S test set.

Minimal test set results:

mmwohl@unicorn:/molmicro/working/molly/src/dada2-nf$ cat output-minimal/weights.csv sv-01:m3n716-s502,sv-01:m3n716-s502,491 sv-02:m3n701-s502,sv-02:m3n701-s502,315 sv-03:m3n701-s502,sv-03:m3n701-s502,306 sv-04:m3n716-s502,sv-04:m3n716-s502,103 sv-05:m3n716-s502,sv-05:m3n716-s502,65 sv-06:m3n701-s502,sv-06:m3n701-s502,59 sv-07:m3n716-s502,sv-07:m3n716-s502,50 sv-08:m3n701-s502,sv-08:m3n701-s502,41 sv-09:m3n701-s502,sv-09:m3n701-s502,15 sv-10:m3n716-s502,sv-10:m3n716-s502,14 sv-11:m3n716-s502,sv-11:m3n716-s502,6

NGS16S test results:

mmwohl@unicorn:/molmicro/working/molly/src/dada2-nf$ head output-single/weights.csv sv-001:795-4,sv-001:795-4,196 sv-001:795-4,sv-001:795-6,121 sv-001:795-4,sv-001:879-9,49 sv-001:795-4,sv-001:795-3,22 sv-002:795-6,sv-002:795-6,148 sv-002:795-6,sv-002:879-9,140 sv-002:795-6,sv-002:795-4,64 sv-002:795-6,sv-002:795-3,25 sv-003:795-3,sv-003:795-3,149 sv-004:795-4,sv-004:795-4,54 mmwohl@unicorn:/molmicro/working/molly/src/dada2-nf$ tail output-single/weights.csv sv-100:795-3,sv-100:795-3,3 sv-101:795-5,sv-101:795-5,3 sv-102:795-5,sv-102:795-5,3 sv-103:795-3,sv-103:795-3,3 sv-104:879-9,sv-104:879-9,3 sv-105:795-5,sv-105:795-5,2 sv-106:795-5,sv-106:795-5,2 sv-107:795-3,sv-107:795-3,2 sv-108:795-3,sv-108:795-3,2 sv-109:795-3,sv-109:795-3,2