Loading from a localhost url network error
**Which version of the plugin are you using?**
[ ] Data Populator for Sketch
[X] Data Populator for Adobe XD

**Describe the bug**
When using "Populate from URL" with a local url. the json does not load

**To Reproduce**
Steps to reproduce the behavior:
1. Go to "Plugins>Data Populator>Populate from URL"
2. Enter a url of a local url running in docker

The preview pane says it is "Unable to preview JSON" and the Developer Console shows "@datapop | TypeError: Network request failed"

**Expected behavior**
The JSON from the url will load in the preview pane.

**Environment (please complete the following information):**
 - macOS Version: [Mojave 10.14.2]
 -  Adobe XD Version [18.0.12.9 Starter]
 - Plugin Version [1.1.4]

**Additional context**
Data loading from urls hosted on the web works just fine. Saving the local url as a file and loading it with "Populate with JSON" works. 