Fix fatal when searching for "r matey prepare to be boarded"

Summary:
See https://discourse.phabricator-community.org/t/unrecoverable-fatal-error-on-repository-search-in-top-search-bar/503/2.

The Ferret engine replaced withNameContains(), but I missed this obscure callsite.

Test Plan:

• Searched for r matey prepare to be boarded.
• Before: fatal.
• After: no fatal.
• Also searched for r <actual repository name>, got repository.

Reviewers: amckinley

Reviewed By: amckinley

Differential Revision: https://secure.phabricator.com/D18661