Run annex.thawcontent-command before deleting an object file

In case annex.freezecontent-command did something that would prevent
deletion.

Sponsored-by: Dartmouth College's Datalad project

Annex/Perms.hs

@@ -29,6 +29,7 @@ module Annex.Perms (
 	modifyContent,
 	withShared,
 	hasFreezeHook,
+	hasThawHook,
 ) where
 
 import Annex.Common
@@ -301,6 +302,9 @@ modifyContent f a = do
 hasFreezeHook :: Annex Bool
 hasFreezeHook = isJust . annexFreezeContentCommand <$> Annex.getGitConfig
 
+hasThawHook :: Annex Bool
+hasThawHook = isJust . annexThawContentCommand <$> Annex.getGitConfig
+
 freezeHook :: RawFilePath -> Annex ()
 freezeHook p = maybe noop go =<< annexFreezeContentCommand <$> Annex.getGitConfig
   where