fix legacy network remap

When I created the original, legacy network remap fields, some indexes were listed twice (i.e. 6).  If deployed this would result in two slices sharing one IP.  This has not occurred with two deployed-to-production slices.

Duplicate entries were due to the original, legacy network remap being constructed from deployed slice configurations, and the fact that not all 12 slice slots were occupied at the time.  In most cases, the default value for index six (the number '6') remained it's default value, even when in-use by another slice.

This patch corrects the entries for index six.  And, I have verified that all 12 values are distinct.

The legacy_network_remap can be retired once we have a solution for long-term-storage of slicename-to-IP mappings for researchers doing long-term studies.  For now, the legacy network remap keeps things as they have always been.