npmrc registry config not always used

[jbedard]

When putting a non-existing URL in the registry or @scope:registry it is not respected and still fetches from the default.

When configuring a non-existing registry the build still passes. For example:

registry=http://notexistingdns.company.internal/repository/TEST-NPM-Group/
@types:registry=http://notexistingdns.company.internal/repository/TEST-NPM-Group/