Fix regression of #1667

[DL6ER]

What does this implement/fix?

Subdomains beginning and ending in dash are actually fine (pattern [a-z0-9_-]{0,63}\.), move the corresponding tests to a concluding TLD check region (pattern [a-z0-9][a-z0-9-]{0,61}[a-z0-9])

Related issue or feature (if applicable): N/A

Pull request in docs with documentation (if applicable): N/A

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[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/gravity-domain-filtering-different/65726/4

[PromoFaux]

Tested against the blocklist in use for the initial but report and confirm that the issue is no longer present

[i] Target: https://raw.githubusercontent.com/chadmayfield/my-pihole-blocklists/master/lists/pi_blocklist_porn_all.list
  [✓] Status: Retrieval successful
  [✓] Parsed 1906594 exact domains and 0 ABP-style domains (blocking, ignored 0 non-domain entries)
  [i] List stayed unchanged