[commit: ghc] master: Update xhtml submodule (a04cfcf)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/a04cfcfb50078ace5f5efb797f1bf544d975b520/ghc

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commit a04cfcfb50078ace5f5efb797f1bf544d975b520
Author: Herbert Valerio Riedel <hvr at gnu.org>
Date:   Thu Sep 7 00:59:28 2017 +0200

    Update xhtml submodule
    
    This fixes a minor thinko about future module exports
    related to Semigroup/Monoid


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a04cfcfb50078ace5f5efb797f1bf544d975b520
 libraries/xhtml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/xhtml b/libraries/xhtml
index 6358594..c5c623e 160000
--- a/libraries/xhtml
+++ b/libraries/xhtml
@@ -1 +1 @@
-Subproject commit 6358594eb5139f6760e2ada72718d69fed5a1015
+Subproject commit c5c623e497f13ec187e0d228e0e8a3d9ee39a715