He was standing around, minding his own business, Julian Rhind-Tutt tells Zoe Williams, when he got 'very, very lucky' and became an actor. Couldn't talent, she asks, have had something to do with it?Modern telly can be a wonderful thing: 10 or 15 years ago, actors would be waiting for a show like Channel 4's Green Wing, the hospital comedy with no patients, to use as a launch pad so they could spring on to something…