Commit 5ea20d5e authored by Hans-Peter Deifel's avatar Hans-Peter Deifel 🐢

Fix build with latest hackage revision of 'json'

There was a revision of the json packages on hackage that changed the
constraints on base, leading to it not building any more for me. This flag
change fixes it.

See also http://hackage.haskell.org/package/json-0.9.3/revisions/
parent 87540f49