webp file in sketch JSON input crash
**Which version of the plugin are you using?**
[ ✅ ] Data Populator for Sketch
[ ] Data Populator for Adobe XD

**Describe the bug**
A clear and concise description of what the bug is.
image url http://www.aaa.com/image.webp  import to image and crash

**To Reproduce**
Steps to reproduce the behavior:
1. click symbols that  above image and text 
2. open plugin populate with JSON
3. choose JSON file that image url .webp 
4. populate and crash

**Expected behavior**
A clear and concise description of what you expected to happen.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Environment (please complete the following information):**
 - macOS Version: [e.g. macOS High Sierra 10.14.6]
 - Sketch Version [e.g. Sketch 68.2] 
 - Plugin Version [e.g. 3.6.4]

**Additional context**
Add any other context about the problem here.
