Fix formatting of message when retrying clone

Passing the force_sync variable into the string formatting results in
the message:

  "Retrying clone after deleting None"

or

  "Retrying clone after deleting True".

Pass the name of the git directory instead.

Also, move the print inside the if-block so it's only displayed
when the retry is actually going to be attempted.

Change-Id: I76d9ecc176cecee4ad512d13e9d1f6bd36aacbbb
diff --git a/project.py b/project.py
index a117f4d..ac60ccc 100644
--- a/project.py
+++ b/project.py
@@ -2182,8 +2182,8 @@
         try:
           self._CheckDirReference(self.objdir, self.gitdir, share_refs=False)
         except GitError as e:
-          print("Retrying clone after deleting %s" % force_sync, file=sys.stderr)
           if force_sync:
+            print("Retrying clone after deleting %s" % self.gitdir, file=sys.stderr)
             try:
               shutil.rmtree(os.path.realpath(self.gitdir))
               if self.worktree and os.path.exists(