Implemented compressed file detection.

src/main/java/info/fetter/logstashforwarder/FileReader.java

@@ -105,6 +105,7 @@ public class FileReader {
 					continue;
 				}
 				if(Arrays.equals(magic, fileBytes)) {
+					logger.debug("Compressed file detected : " + state.getFile());
 					return true;
 				}
 			}