Update data.sql to drop all existing entries at restart

backend/src/main/resources/data.sql

@@ -1,3 +1,8 @@
+SET FOREIGN_KEY_CHECKS=0;
+
+DELETE FROM timetrack_user;
+DELETE FROM role;
+
 INSERT INTO role (id, `name`) VALUES
   (1, 'Admin');
 
@@ -10,3 +15,4 @@ INSERT INTO timetrack_user (id, firstname, lastname, password, username, role_id
   (3, 'Tim', 'Zieger' ,'$2y$10$pYGHZhoaelceImO7aIN4nOkWJBp.oqNGFYaRAonHkYF4u9ljqPelC', 'ziti', 1),
   (4, 'Simon', 'Kellner' ,'$2y$10$Puzm/Nr/Dyq3nQxlkXGIfubS5JPtXJSOf2e6mrQ6HhVYQN9YiQQsC', 'kesi', 1);
 
+SET FOREIGN_KEY_CHECKS=1;