switch to info log level when reporting session expiration

Current Situation

• The Controller log reports

• 2025-07-16T00:07:05,350 WARN  js7.common.http.RecouplingStreamReader -  HttpControllerApi(http://<some-host>:4444): coupling failed: InvalidSessionToken: Invalid session token
  2025-07-16T00:07:06,382 info  js7.common.http.RecouplingStreamReader -  Streaming HttpControllerApi(<some-host>:4444) ...
  ...
  2025-07-16T01:07:15,255 WARN  js7.common.http.RecouplingStreamReader -  HttpControllerApi(http://<some-host>:4444): coupling failed: InvalidSessionToken: Invalid session token
  2025-07-16T01:07:16,292 info  js7.common.http.RecouplingStreamReader -  Streaming HttpControllerApi(http://<some-host>:4444) ...
  

• Above messages do not indicate an error but normal expiration of sessions between Controller instances in a cluster. Sessions are renewed after a 60 minutes' idle timeout.

Desired Behavior

• The "Invalid session token" message should be reported at info level