`exportWithBackgroundImage` does not work when background image is set using datauri
**Describe the bug**
First of all, this project is awesome. However, what is preventing me from using it, is that there is a bug when adding a backgroundImage from a dataURI, and then attempting to export the image **without the background image**

**To Reproduce**
To reproduce
1. Go to [the demo](https://vinoth.info/react-sketch-canvas/)
2. Add a background image from a dataURI (Can be anything)
3. Add some strokes
4. Uncheck `exportWithBackgroundImage` 
5. Export Image

**Expected behavior**
Image is exported **without** the background image.

**Actual behavior**
Image is exported **with** the background image. Note: The SVG is exported correctly, without the background image. 

**Screenshots**
<img width="1792" alt="Screen Shot 2022-12-29 at 4 35 06 PM" src="https://user-images.githubusercontent.com/36947377/210013233-4945c741-f165-49bd-89ec-dab1f8c30228.png">

**Desktop (please complete the following information):**
 - OS: Mac OS
 - Browser: Chrome