use special logger for insertion metrics

This allows us to enable/disable metric logging without having to log 
other stuff.

pdb-ui/src/main/java/org/lucares/pdbui/TcpIngestor.java

@@ -102,7 +102,7 @@ public class TcpIngestor implements Ingestor, AutoCloseable, DisposableBean {
 					}
 
 					if (entry.isPresent()) {
-						LOGGER.trace("adding entry to queue: {}", entry);
+						LOGGER.debug("adding entry to queue: {}", entry);
 						queue.put(entry.get());
 					}