fixes historical sync zero index bug

[chavesj]

Description

Title says it all, see ticket: https://klaviyo.tpondemand.com/entity/170341-magento-2-customers-historical-sync

Manual Testing Steps

1.

Pre-Submission Checklist:

• [ ] You've updated the CHANGELOG following the steps here
• [ ] Internal Only - If this is a release, please confirm the following:
  • [ ] The links in the changelog have been updated to point towards the new versions
  • [ ] The version has been incremented in the following places: module.xml and composer.json

NOTE: Please use the Changelogger cli tool to manage versioned file upgrades.