Fetching external dependencies log entry is printed even if there are not dependencies

The below log entry is currently printed when downloading an npm package through a virtual repository, even if there are no dependencies:

2016-02-22 16:46:33,227 [http-nio-8080-exec-3] [INFO ] (o.a.a.n.r.m.NpmPackageMetadataMerger:143) Fetching external dependencies for 'test-package' from 'npm-local'

Artifactory should print this log entry only when fetching a package external dependencies.