Migration should be Acid

Author: isovector

src/Distribution/Server/Features/Security/Migration.hs

@@ -31,7 +31,7 @@ import Distribution.Server.Features.Security.Layout
 import Distribution.Server.Framework hiding (Length)
 import Distribution.Server.Framework.BlobStorage
 import Distribution.Server.Packages.Types
-import Distribution.Server.Packages.Utils
+import Distribution.Server.Packages.Utils.Acid
 import Distribution.Server.Util.ReadDigest
 import qualified Distribution.Server.Packages.PackageIndex as PackageIndex