R1:1dd91bde1ff9

Implement option 1 from T3210

Summary: Fixes T3210

Test Plan: Run the conduit call via the UI and ensure it no longer breaks. Check I get an error returned if no params are set

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T3210

Differential Revision: https://secure.phabricator.com/D5950