http://<controller:8181>/restconf/streams json has broken when we make websocket request

Steps to reproduce:

1)
Restconf URL: http://<controller-ip>:8181/restconf/operations/sal-remote:create-data-change-event-subscription
Payload:
{
"input":

{ "path": "/network-topology:network-topology", "datastore": "OPERATIONAL", "scope": "SUBTREE" }

}

Request: POST

2) http://<controller-ip>:8181/restconf/streams : gives 500 Internal server error when content-type: application/json Accept: application/json

Note: http://<controller-ip>:8181/restconf/streams : gives 200 response code when content-type: application/xml Accept: application/xml