conn: MetricsPort listener is a listener port

The connection type for the listener part was missing from the "is
connection a listener" function.

This lead to our periodic event that retries our listeners to keep
trying to bind() again on an already opened MetricsPort.

Closes #40370

Signed-off-by: David Goulet <dgoulet@torproject.org>
9 jobs for ticket40370_045_01 in 17 minutes and 7 seconds (queued for 1 second)
latest