Improve Logger calls

- Replace various deprecated Logger::log calls
- Reassign log level for verbose log calls

src/Protocol/DFRN.php

@@ -1546,7 +1546,7 @@ class DFRN
 			$author["network"] = $contact_old["network"];
 		} else {
 			if (!$onlyfetch) {
-				Logger::log("Contact ".$author["link"]." wasn't found for user ".$importer["importer_uid"]." XML: ".$xml, Logger::DEBUG);
+				Logger::debug("Contact ".$author["link"]." wasn't found for user ".$importer["importer_uid"]." XML: ".$xml);
 			}
 
 			$author["contact-unknown"] = true;