fix: gomplate now upgrades with the v

[jessesimpson36]

Which problem does the PR fix?

Our renovate configuration had a problem which was causing it to not process any packageRules for gomplate, because the packageName is actually hairyhenderson/gomplate and not just gomplate. Furthermore, the v has to be inside the named regex named "currentVersion" for it to be recognized as necessary for the new version.

Here's my evidence of it working:
jessesimpson36/renovate-gomplate-test#3

What's in this PR?

Checklist

Please make sure to follow our Contributing Guide.

Before opening the PR:

• In the repo's root dir, run make go.update-golden-only.
• There is no other open pull request for the same update/change.
• Tests for charts are added (if needed).
• In-repo documentation are updated (if needed).

After opening the PR:

• Did you sign our CLA (Contributor License Agreement)? It will show once you open the PR.
• Did all checks/tests pass in the PR?

[aabouzaid]

LGTM, thank you 👍