Killing eventing producer caused paused handler to hung in pausing

Build: 7.0.0-4454

• create 2 node cluster 1 eventing , 1 KV
• deploy 1 handler and pause the handler
• rebalance in 1 eventing node, wait for rebalance to complete
• kill producer on 1 node
• Observed handler hung in pausing and rebalance button become enabled
• It paused when we trigger rebalance 

{    "apps": [        {            "composite_status": "pausing",            "name": "test",            "num_bootstrapping_nodes": 0,            "num_deployed_nodes": 1,            "deployment_status": true,            "processing_status": false        }    ],    "num_eventing_nodes": 2}