repository: update interface signature of narrowmatch() This should have been part of 4fd0fac48922 (localrepo: allow narrowmatch() to accept matcher to intersect with, 2018-09-28) and 41fcdfe3bfeb (narrow: allow repo.narrowmatch(match) to include exact matches from "match", 2018-10-01). Differential Revision: https://phab.mercurial-scm.org/D5466