Export Error when Exporting PDF

[Mitrimo]

Current behavior

When trying to export a simple note with pure text and one link to another site (like this), the program reports an
Export error
callback must be a function

This happens under Windows 10 Pro, Version 1803 with Boostnote Version 0.11.17. .md and .html exports work flawlessly.

Expected behavior

Exporting a regular plaintext .pdf.

Environment

• Version : 0.11.17
• OS Version and name : Windows 10 Pro Version 1803

[amedora]

duplicates #2968, will be resolved by #3048 .