Empty description is exported to .png and .svg as "undefined"

[hofstef]

Describe the bug
If the description of a story is left empty, image exports (.egn.svg and .png) contain the string "undefined".

Expected behavior
When there is no description , then it should be completely omitted from the generated images.

Screenshots

Version

• Egon: v2.2.0
• Browser: Firefox, Chrome

[hofstef]

fixed in v2.4.0