fix(stackSync): Don't throw NPE if options is empty #795

[wayfarer3130]

Context

The stack image sync changes added a reference to options that didn't use ?. so it was throwing a NPE if options wasn't set.

Changes & Results

Testing

Checklist

PR

• [] My Pull Request title is descriptive, accurate and follows the
  semantic-release format and guidelines.

Code

• [] My code has been well-documented (function documentation, inline comments,
  etc.)

• [] I have run the yarn build:update-api to update the API documentation, and have
  committed the changes to this PR. (Read more here https://www.cornerstonejs.org/docs/contribute/update-api)

Public Documentation Updates

• [] The documentation page has been updated as necessary for any public API
  additions or removals.

Tested Environment

• [] "OS:
• [] "Node version:
• [] "Browser:

[netlify]

✅ Deploy Preview for cornerstone-3d-docs ready!

Name	Link
🔨 Latest commit	e47518d
🔍 Latest deploy log	https://app.netlify.com/sites/cornerstone-3d-docs/deploys/6511a9dce272ca0008c2344c
😎 Deploy Preview	https://deploy-preview-799--cornerstone-3d-docs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.