tests: fix test-casefolding.t output for branchcache
This belongs with 7d63398fbfd1. I assume that the failure to read is OK,
because there is similar output in test-convert-svn-encoding.t.
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ echo 'base' > base
$ hg ci -Ambase
adding base
$ hg qnew -mmqbase mqbase
$ hg qsave
$ hg qrestore 2
restoring status: hg patches saved state