[lxd-import] client: Always use event listener for operations.

When long polling the operation wait endpoint, we can never guarantee
that the request will not time out for very long operations (e.g. an
exec session) because intermediate proxies or load balancers may timeout
the request if there is no activity. This commit changes the
`useEventListener` argument to getOperations to true for all requests.
Regardless of whether the `operation_wait` API extension is present.

Signed-off-by: Mark Laing <mark.laing@canonical.com>

client/incus_instances.go

@@ -1112,8 +1112,7 @@ func (r *ProtocolIncus) ExecInstance(instanceName string, exec api.InstanceExecP
 	}
 
 	// Send the request
-	useEventListener := r.CheckExtension("operation_wait") != nil
-	op, _, err := r.queryOperation("POST", uri, exec, "", useEventListener)
+	op, _, err := r.queryOperation("POST", uri, exec, "", true)
 	if err != nil {
 		return nil, err
 	}