Get rid of localDir.

This param went away.  epriestley just told me in IRC:

[12:05]	epriestley   It has been on the way out for a while since it's a security issue (see T4039 for some discussion).
[12:05]	epriestley   The default will be `repository.default-local-path` plus the repo callsign, e.g. /var/repo/XYZ

That works for us.

Auditors: alpert

Test Plan:
Fingers crossed