XEP-0184 requests send to resources not supporting them
Bug description
Gajim sends requests for message delivery receipts (XEP-0184) to any resource, as long as one connected resource supports them. This is currently biting me when chatting with a contact that is connected with both yaxim (support 184) and Pidgin (doesn't support 184). The resource is locked on to Pidgin after the first reply, but message delivery receipts are still requested, although unsupported. This causes spurious "delivery likely failed" icons to appear.