Update ShipWarfare.java

somehow, the comment doesn't let me compile the file.

src/ShipWarfare.java

@@ -2,13 +2,6 @@ import java.util.Scanner;
 import java.util.Random;
 import java.util.concurrent.TimeUnit;
 
-/*
-
-Learned how to use the Time Unit Class from the following source:
-Slim, and Lalith Verma. “How to Use TimeUnit in Java.” Stack Overflow, 8 Dec. 2017, stackoverflow.com/questions/47717633/how-to-use-timeunit-in-java.
-
-*/
-
 public class ShipWarfare extends Player {
 
     private int numOfPeasantShips = 0;