Use "getInlines()", not "_inlines", to access inlines on client Changeset objects
See PHI1898. An install is reporting an execution/initialization order issue where this code is reachable before _inlines is initialized.
I can't immediately reproduce it, but using "getInlines()" is preferable anyway and seems likely to fix the problem.
Test Plan: Viewed revisions with inlines, added/removed/edited/replied to inlines, didn't find anything broken.
Differential Revision: https://secure.phabricator.com/D21475