From https://github.com/tigase/tigase-server/issues/141

Describe the bug

According to https://datatracker.ietf.org/doc/html/rfc7395#section-3.8

whitespace keepalives are not allowed with Websocket connection

But Tigase still provides an option to do so https://github.com/tigase/tigase-server/blob/master/src/main/java/tigase/server/ConnectionManager.java#L1485

which may lead to crashes in clients XMPP libs , e.g. https://github.com/xmppjs/xmpp.js/issues/942

To Reproduce Steps to reproduce the behavior:

1. create a nodejs client with xmppjs lib
2. connect to Tigase server
3. wait 30 mins until the crash occur

Impact Tigase starts but the default behaviour of a 'dead connection detection function' can lead to random crashes at clients side

Expected behavior To have a more artificial logic in Tigase, e.g. send whitespace chars for non WS and ping for WS clients