According to a brief post by Daring Fireball’s John Gruber, Apple will release the final version of iOS 7.1 “any day now,” ahead of next week’s iTunes Festival at South By Southwest (SXSW) in Austin, Texas. Alluding to an unnamed source at Apple, Gruber notes that “a little birdie” told him that the iTunes Festival live streaming application requires iOS 7.1, so the long-awaited bug-fixing iOS update would logically…