Patch OneTuple to work around ghc#20562 on HEAD

patches/OneTuple-0.3.1.patch

+diff --git a/src/Data/Tuple/OneTuple.hs b/src/Data/Tuple/OneTuple.hs
+index 8700132..cb7feb0 100644
+--- a/src/Data/Tuple/OneTuple.hs
++++ b/src/Data/Tuple/OneTuple.hs
+@@ -21,7 +21,7 @@ import Data.Tuple.Solo
+ type OneTuple = Solo
+ 
+ only :: OneTuple a -> a
+-only = getSolo
++only (Solo x) = x
+ 
+ #if __GLASGOW_HASKELL__ >= 708
+ #if __GLASGOW_HASKELL__ >= 710