Our current npm repository behaviour:
1. Request a package tgz through a proxy repository that exists in the remote. 404 not found
2. Request the metadata for that package. 200 response and package url in step 1 says to get it from Nexus
3. Try to get the package again from Nexus - still 404, cached not found.
Expected: Nexus should try to be more forgiving when a package file is requested before metadata.