wee-slack: websocket connection error: cafile, capath and cadata cannot be all omitted

I got the following error when I try to load the slack plugin:

python: stdout/stderr: websocket connection error: cafile, capath and cadata cannot be all omitted
python: stdout/stderr: websocket connection error: cafile, capath and cadata cannot be all omitted

After this it just infinitely tries to reconnect to slack without success.

I think this might have been due to some upgrade of libraries but not sure. Any pointers in the right direction would be appreciated or of this is actually a bug in wee-slack.