dirstate-item: make sure we load `mtime-second-ambiguous` from disk Now that we support the associated logic, we can safely load it from it. It is no longer necessary to ignore the stored mtime when the flag is encountered. Differential Revision: https://phab.mercurial-scm.org/D11846

[workspace]
members = ["hg-core", "hg-cpython", "rhg"]
exclude = ["chg", "hgcli"]