OMEMO encrypted messages are not sent with Gajim 0.16.5

• OMEMO-Plugin: 1.2.3
• Gajim: 0.16.5
• Ubuntu Xenial

The commit 1336c618 breaks sending OMEMO encrypted messages at least with the above mentioned Gajim version.

Log:

(D) gajim.plugin_system.omemo 'StanzaMessageOutgoingEvent' object has no attribute '_cb_parameters'