Remove unnecessary import.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Cabal/Distribution/Simple/LocalBuildInfo.hs

@@ -90,7 +90,6 @@ import Data.List (nub, find, stripPrefix)
 import Data.Maybe
 import Data.Tree  (flatten)
 import GHC.Generics (Generic)
-import Data.Map (Map)
 import System.FilePath
 
 import System.Directory (doesDirectoryExist, canonicalizePath)