[IMP] hide contract link from project view if customer is not define

- Task: https://www.odoo.com/web#id=7413&view_type=form&model=project.task&menu_id=3942&action=327
- Pad: https://pad.odoo.com/p/r.KhHBgxwl04WHFjTW
Hello @tde, When Only Project installed, at that time. 'Project Manager' and 'Customer' fields are not in proper align. Thats why add new group name='align' in project view. And manage contract link in same line, need to change xpath with new group name='align'.