Nexus $registry.host to tpl

Package Merge Request

Package Changes

https://repo1.dso.mil/platform-one/big-bang/apps/developer-tools/nexus/-/blob/41.1.0-bb.5/CHANGELOG.md

Package MR

https://repo1.dso.mil/platform-one/big-bang/apps/developer-tools/nexus/-/merge_requests/55

Closes https://repo1.dso.mil/platform-one/big-bang/apps/developer-tools/nexus/-/issues/39