remotefilelogserver: add a matcher argument to _walkstreamfiles()
Implementing narrow stream clones in core, I added an optional matcher argument.
The function in remotefilelogserver.py does not know about that argument and
does not accept that and hence some tests fails.
Differential Revision: https://phab.mercurial-scm.org/D5191
#require docutils gettext
$ $TESTDIR/check-gendoc zh_TW
checking for parse errors