[commit: ghc] master: Update `pretty` submodule to v1.1.3.3 release (15b7e87)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/15b7e87702e4407d006a64c906a7c03f3fdf164e/ghc

>---------------------------------------------------------------

commit 15b7e87702e4407d006a64c906a7c03f3fdf164e
Author: Herbert Valerio Riedel <hvr at gnu.org>
Date:   Tue Apr 19 23:09:15 2016 +0200

    Update `pretty` submodule to v1.1.3.3 release


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15b7e87702e4407d006a64c906a7c03f3fdf164e
 libraries/pretty | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/pretty b/libraries/pretty
index 9fd5f2b..56bc78e 160000
--- a/libraries/pretty
+++ b/libraries/pretty
@@ -1 +1 @@
-Subproject commit 9fd5f2b596bdfbce0414f973009b579d5d2430fa
+Subproject commit 56bc78e2c2cfcc850f6fec87fe79743750d4c8b4