Increase sleep time in test even more

Author: sungshik

src/test/java/engineering/swat/watch/SingleDirectoryTests.java

@@ -225,6 +225,7 @@ void indexingRescanOnOverflow() throws IOException, InterruptedException {
 
             var overflow = new WatchEvent(WatchEvent.Kind.OVERFLOW, directory);
             ((EventHandlingWatch) watch).handleEvent(overflow);
+            Thread.sleep(TestHelper.NORMAL_WAIT.toMillis());
             Thread.sleep(TestHelper.LONG_WAIT.toMillis());
             // At this point, the current thread has presumably slept long
             // enough for the `OVERFLOW` event to have been handled by the