fix init in cripped filesystem version issues

* init: When a crippled filesystem causes an adjusted unlocked branch to
  be used, set repo version to 7, which it neglected to do before.
* init: When on a crippled filesystem, and the git version is too old
  to use an adjusted unlocked branch, fall back to using direct mode.

This commit was sponsored by Ilya Shlyakhter on Patreon.

Annex/AdjustedBranch.hs

@@ -28,6 +28,7 @@ module Annex.AdjustedBranch (
 	checkAdjustedClone,
 	isSupported,
 	checkVersionSupported,
+	isGitVersionSupported,
 ) where
 
 import Annex.Common
@@ -227,6 +228,7 @@ updateAdjustedBranch adj@(LinkAdjustment _) _ origbranch = preventCommits $ \com
 adjustToCrippledFileSystem :: Annex ()
 adjustToCrippledFileSystem = do
 	warning "Entering an adjusted branch where files are unlocked as this filesystem does not support locked files."
+	checkVersionSupported
 	whenM (isNothing <$> originalBranch) $
 		void $ inRepo $ Git.Branch.commitCommand Git.Branch.AutomaticCommit
 			[ Param "--quiet"