hg: perform update after pulling during clone with share (issue5103) When pooled storage is enabled, `hg clone` will initialize a repo from a local repo using the store sharing mechanism then pull from the originally requested repo. Before this patch, the working directory update occurred between these steps. This meant that we would only update to revisions that were already present in the local pooled storage. This patch moves the update to after we pull from the originally requested repository so we may check out a revision that didn't yet exist locally. In other words, it makes the behavior like normal `hg clone`.