[OMEMO] Gajim should use "current" id when setting bundle
Currently OMEMO plugin is not specifying item
id when pushing bundle. A a result, each new item is added to the node instead of replacing the first one, and the node is growing indefinitely. If
pubsub#max_items is set to 1, the node won't grow indefinitely, but this settings is not mandatory (and not even specified beside being in examples) in XEP-0060.
As XEP-0060 states, it is recommanded to use "current" as id when using a singleton Pubsub node, so Gajim should use "current" id when storing bundle.