context: audit paths before clearing unknown files and dirs
Fix regression introduced in D785.
In some circumstances, context.clearunknown can be called before the path is
audited. Audit the path before deleting any conflicting files.
Differential Revision: https://phab.mercurial-scm.org/D1157
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}