converse.js: HTTP file upload failed

Refused to connect to 'https://cweiske.de:5444/asdf/asdf/6x6.png' because it violates the following Content Security Policy directive: "connect-src 'self' conversejs.org".

uploadFile @ converse.min.js:47274

This is a configuration problem on the server hosting conversejs. It needs to allow PUT to other servers in its CSP.