sync, assistant: When merge.directoryRenames is not set, default it it to "false"

Works better with automatic merge conflict resolution than git's ususual
default of "conflict".

This is not done when automatic merge conflict resolution is disabled.

This commit was sponsored by Mark Reidenbach on Patreon.

Types/GitConfig.hs

@@ -130,6 +130,7 @@ data GitConfig = GitConfig
 	, receiveDenyCurrentBranch :: DenyCurrentBranch
 	, gcryptId :: Maybe String
 	, gpgCmd :: GpgCmd
+	, mergeDirectoryRenames :: Maybe String
 	}
 
 extractGitConfig :: ConfigSource -> Git.Repo -> GitConfig
@@ -223,6 +224,7 @@ extractGitConfig configsource r = GitConfig
 	, receiveDenyCurrentBranch = getDenyCurrentBranch r
 	, gcryptId = getmaybe "core.gcrypt-id"
 	, gpgCmd = mkGpgCmd (getmaybe "gpg.program")
+	, mergeDirectoryRenames = getmaybe "directoryrenames"
 	}
   where
 	getbool k d = fromMaybe d $ getmaybebool k