Update one more Mac OS X reference to macOS

bertday · bertday · commit f80db220e159 · 2018-05-16T23:24:00.000-04:00
diff --git a/docs/shipping/freezing.rst b/docs/shipping/freezing.rst
@@ -14,8 +14,8 @@ Applications such as 'Dropbox', 'Eve Online',  'Civilization IV', and
 BitTorrent clients do this.
 
 The advantage of distributing this way is that your application will "just work",
-even if the user doesn't already have the required version of Python (or any) 
-installed. On Windows, and even on many Linux distributions and OS X, the right
+even if the user doesn't already have the required version of Python (or any)
+installed. On Windows, and even on many Linux distributions and macOS, the right
 version of Python will not already be installed.
 
 Besides, end-user software should always be in an executable format. Files 
