dhall-json_1_2_0: fix dependencies

dhall-json 1.2.0 requires dhall's version to be at least 1.14.0 and less
than 1.15.0.  The package wasn't building for me because `dhall` is at
version 1.11.1; pinning to `dhall_1_14_0` fixed it.

pkgs/development/haskell-modules/configuration-common.nix

@@ -1051,6 +1051,8 @@ self: super: {
     strictDeps = true;
   });
 
+  # dhall-json requires a very particular dhall version
+  dhall-json_1_2_0 = super.dhall-json_1_2_0.override { dhall = self.dhall_1_14_0; };
 }
 
 //