src.ctf.lttng-live: LOGI instead of LOGW when getting queried for an unknown object

src.ctf.lttng-live: LOGI instead of LOGW when getting queried for an unknown object

Receiving a query about an unknown object happens in the normal course
of operations, and is not warning-worthy.  In particular, a following
patch will query all source component classes using the `support-info`
object, to see if the source component class supports a given input.
Having a LOGW here would generate a lot of unimportant warnings.

Change-Id: I067424cb72f78aeda6ce6791b12fa00d7d90b5c0
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1741
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>