evolve: fix progress display with hg<4.7
Since d1aab9d82f5b (evolve: adapt for deprecated ui.progress(),
2019-01-14), the "item", "units" and "total" are all set to default
values. The last one is especially bad since it results in a "spinner"
instead of a progress bar.
Test that share-clones use the cache in the original repository.
$ . $TESTDIR/testlib/common.sh
$ hg init share-base
$ cd share-base/
$ cat >> .hg/hgrc <<EOF
> [extensions]
> evolve=
> share=
> EOF
$ hg debugbuilddag .+3:branchpoint+4*branchpoint+2
$ cd ..
$ hg --config extensions.share= share -U share-base share-client
$ cd share-client
$ hg debugupdatecache
$ test -d .hg/cache
[1]
$ test -d ../share-base/.hg/cache