Defer creating logger in StandardWebSocketHandlerAdapter

[quaff]

Defer creating logger for StandardWebSocketHandlerAdapter to avoid early log4j2 initializing

Fix #25427

[jhoeller]

According to the lifecycle of such endpoint classes, it looks like it will be sufficient to change the logger field to non-static, allowing for reuse of the Log instance and for earlier detection of logger configuration problems. Unless you see problems with this, I'm going to proceed with such a field-level change against your original report, backporting it all the way down to the 4.3.x line.

Thanks for the PR, in any case! And good timing there, we got the whole range of backport releases scheduled for tomorrow...