OTR improvments
A couple of things need to be done with OTR:
- OTR v3 is now implemented in python-otr, need to update the plugin to handle that
- ?OTRv2 in the middle of the message trigger OTR discovery
- there should be an option to disable OTR discovery through OTR itself, it should probably not be used by default (check new XEP about OTR discovery with XMPP)
- OTR should not be enabled at all for groupchat