Rich text from LibreOffice Calc is sent as screenshots

[dca00]

Describe the bug

Pasting content from LibreOffice Calc results in it being immediately sent as a screenshot.

To Reproduce Steps to reproduce the behavior:

1. Copy cells from LibreOffice Calc
2. Paste into a new IM
3. See it being sent immediately

Expected behavior

Rich text from Calc should be pasted into a new message, for editing and sending whenever the user wants

Screenshots

Environment (please complete the following information):

• Desktop
• Browser Firefox]
• Converse.js version [e.g. 12.0.0]

Additional context

Both usability and security is compromised by this issue