XMPP

Especially for IRC, the outgoing IP address can matter a lot. Need some way to set which one to use on a box that has many.

Describe the bug
If I close a chat browser tab( auto_login:true and view_mode: 'fullscreen') without logout and reopen it in the new tab, file upload button is missing.

To Reproduce
Steps to reproduce the behavior:

1. Open new chat window(auto_login:true and view_mode: 'fullscreen')
2. Open same chat window in separate browser tab without log out previous tab.
3. See error - upload

https://github.com/dino/dino/blob/7ce49d7d68f19fb49a33e907485d83da2c9131a3/plugins/omemo/src/file_transfer/file_encryptor.vala#L41

That's not a valid MIME type.

If the goal is to hide the real content type, why not set it to application/octet-stream or something overly generic like that?

For the feature Private key transfer #1090 you use Barcodes for verification.
Would it be a good idea to use the same way to verify Public key of contacts and mark this verificated users in contactlist with a green Icon or somewhat (similar to Threema )?

Maybe:
-yellow for "I'm not sure but I trust the key anyway and will verify it by our next beer."
-green for "I have scanned the code of m