Melinda Doolittle says Nicole Kidman advised her to hire security. The 44-year-old singer finished in third place on ‘American Idol’ back in 2007 and was being inundated by fans at a restaurant but was surprised to see that Hollywood actress Nicole, 55, was being left in peace at a nearby table. She said: “Nobody was talking to Nicole. I had a line at my table and I was like, ‘I do not understand, Nicole Kidman is right there. [When I got up] , Nicole was like, ‘Hey, honey, we’re so proud of you!’ We watched you on the show. And I just want to tell you to invest in security.” The ‘I’m a Woman’…