log INFO for messaging-activemq journal-type

In the messaging-activemq subsystem, the default journal type is AIO.
This type of journal only works on Linux (with LibAIO installed). On any other platforms, we log a WARN that AIO can not be installed and NIO will be used instead.

We should have no WARN log when starting a pristine EAP servers.
However, having AIO by default ensures that on Linux, we provide the best messaging performance out of the box.

Instead of logging a WARN, we should only log an INFO telling the users that AIO can not be loaded and NIO will be used.
There is no functionality problem using NIO instead of AIO, only best performance will not be achieved.