ImageJ2Options: set meaningful default log level

Author: stelfrich

src/main/java/net/imagej/legacy/ImageJ2Options.java

@@ -266,6 +266,6 @@ private String parseLogLevel(int level) {
 		if (level == LogService.TRACE)
 			return "TRACE";
 
-		return "WARN";
+		return "" + level;
 	}
 }