fix Tailer.run race condition runaway logging

Author: davidmoten

src/main/java/org/apache/commons/io/input/Tailer.java

@@ -446,6 +446,7 @@ public void run() {
                     } catch (final FileNotFoundException e) {
                         // in this case we continue to use the previous reader and position values
                         listener.fileNotFound();
+                        Thread.sleep(delayMillis);
                     }
                     continue;
                 } else {