Fix ProjectRepository.addProjectLeaderToProject SQL error

[libanbn]

{
    "timestamp": "2019-12-03T21:54:35.351+0000",
    "status": 500,
    "error": "Internal Server Error",
    "message": "PreparedStatementCallback; SQL [INSERT INTO project_project_leader(project_id, leader_id) \nVALUES (?,        (SELECT pl.leader_id            FROM project_leader pl            INNER JOIN employee_project_leader epl ON epl.employee_id = pl.leader_id            INNER JOIN employees e ON e.employee_id = epl.employee_id            WHERE e.employee_id = ?        ))]; Column 'project_id' cannot be null; nested exception is java.sql.SQLIntegrityConstraintViolationException: Column 'project_id' cannot be null",
    "path": "/addNewProject"
}

[libanbn]

Uncomment line defined in 6dbdba4 when done