update nltk url and task

[estherjsuh]

Changes

• update the download url for "corpora/stopwords"
• include -o overwrite tag to unarchive nltk data task

Configuration Pull Request

Make sure that the following steps are done before merging:

• [ ] A DevOps team member has approved the PR.
• [ ] Are you adding any new default values that need to be overridden when this change goes live? If so:
  • [ ] Update the appropriate internal repo (be sure to update for all our environments)
  • [ ] If you are updating a secure value rather than an internal one, file a DEVOPS ticket with details.
  • [ ] Add an entry to the CHANGELOG.
• [ ] If you are making a complicated change, have you performed the proper testing specified on the Ops Ansible Testing Checklist? Adding a new variable does not require the full list (although testing on a sandbox is a great idea to ensure it links with your downstream code changes).