Added last seen queries

src/main/java/com/alttd/database/Queries.java

@@ -8,7 +8,9 @@ import it.unimi.dsi.fastutil.objects.Object2ObjectArrayMap;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.Date;
 import java.util.UUID;
+import java.util.concurrent.TimeUnit;
 
 public class Queries {
     /**