Spelling: iTunes, bugfixes

As per https://en.wikipedia.org/wiki/ITunes and https://en.wikipedia.org/wiki/Patch_(computing) "bugfix" is preferable, as it avoids the misnomer of "a bug" fixing "something"*

Edit: On June 3, 2019, Apple announced that iTunes will be replaced in macOS Catalina by separate applications for Music, Podcasts, and TV