Selena Gomez was “nervous” about joining the cast of ‘Only Murders in the Building’. The 32-year-old actress made her name as a teenager on the Disney Channel in the leading role of ‘Wizards of Waverly Place’ but carved out a pop career in the years that followed and when she agreed to star in the Apple+ series alongside Steve Martin and Martin Short, it proved to be a major comeback to the small screen for her. Selena – who has been nominated for an Emmy for her role in the series – told Extra: “I was nervous. This was my second TV show that I’d ever done. I was really excited, but I have to …