Parameter to update max amount of simultaneous connections allowed with Websockets

[pablocarle]

Is your feature request related to a problem? Please describe. We have verified with performance tests that the Gateway is using a default value for the maximum amount of simultaneous web socket sessions.

Describe the solution you'd like Provide a parameter, probably similar to the maxConnectionsPerRoute and related, to increase the maximum amount of allowed open websocket connections. We verified with a sample service (such as discoverable client) that the maximum amount of threads directly impacts the amount of simultaneous websocket sessions we can get.

Describe alternatives you've considered Need to verify it, but likely an HA setup would mitigate this, at least in some extent.