Temp hack to fix DemoBench in master: leak the RPC connections when a node shuts down to avoid a hang.

tools/demobench/src/main/kotlin/net/corda/demobench/rpc/NodeRPC.kt

@@ -54,7 +54,8 @@ class NodeRPC(config: NodeConfig, start: (NodeConfig, CordaRPCOps) -> Unit, invo
     override fun close() {
         timer.cancel()
         try {
-            rpcConnection?.close()
+            // TODO: Uncomment when https://github.com/corda/corda/issues/689 is fixed
+            // rpcConnection?.close()
         } catch (e: Exception) {
             log.error("Failed to close RPC connection (Error: {})", e.message)
         }