Simon Cowell hasn’t set a wedding date yet. The ‘X Factor’ boss proposed to long-term partner Lauren Silverman – the mother of his eight-year-old son Eric – in December but despite reports they are planning to tie the knot in London soon, his close friend Sinitta insisted there are no definite plans in place. Sinitta – who is currently on tour with musical ‘Chicago’ – said: “A date hasn’t been set for Simon’s wedding yet – there’s been no invitations, nothing’s happened. “But it’s going to be fantastic when it does. “People were saying I’m going to miss it [while on tour] but I’m not. “I have …