[AG-36] license extraction for some Node.js dependencies is not working

[felipead]

We have a case where a license is declared inside http://registry.npmjs.org/mutationobserver-shim/ as

"license": {
    "type": "WTFPL",
    "version": "v2 2004",
    "url": "http://www.wtfpl.net/"
  }

This is an expected case, but somehow the Node.js is not being able to extract this license. This is a bug.