Merge pull request #4947 from NathanConroy/master

fixed comment typo: 'is' to 'it' [ci skip]

Cabal/Distribution/Text.hs

@@ -8,7 +8,7 @@
 -- Portability :  portable
 --
 -- This defines a 'Text' class which is a bit like the 'Read' and 'Show'
--- classes. The difference is that is uses a modern pretty printer and parser
+-- classes. The difference is that it uses a modern pretty printer and parser
 -- system and the format is not expected to be Haskell concrete syntax but
 -- rather the external human readable representation used by Cabal.
 --