Clarify confusing error message about missing .arcconfig vs missing conduit.
Clarify confusing error message about missing .arcconfig vs missing conduit.

Summary:

Test Plan:

Reviewers:

CC:

alexmv/arcanist,fivestars/arcanist,folsom-labs/arcanist,KieranHayes/arcanist,uber/arcanist,jra3/arcanist,folsom-labs/arcanist,phacility/arcanist,eSpark/arcanist,wikimedia/phabricator-arcanist,phacility/arcanist,wharris/arcanist,codelabs-ch/arcanist,alexmv/arcanist,wharris/arcanist,haskell-infra/arcanist,eSpark/arcanist,haskell-infra/arcanist,jra3/arcanist,phacility/arcanist,coursera/arcanist,dguo-coursera/arcanist,r4nt/arcanist,uber/arcanist,coursera/arcanist,wikimedia/phabricator-arcanist,Symplicity/arcanist,uber/arcanist,alexmv/arcanist,hach-que/arcanist,codelabs-ch/arcanist,PageUpPeopleOrg/arcanist-patches,calblueprint/arcanist,kevinseelbach/arcanist,aik099/arcanist,codelabs-ch/arcanist,calblueprint/arcanist,r4nt/arcanist,zhihu/arcanist,haskell-infra/arcanist,KieranHayes/arcanist,r4nt/arcanist,chundongwang/arcanist,PageUpPeopleOrg/arcanist-patches,folsom-labs/arcanist,PageUpPeopleOrg/arcanist-patches,zhihu/arcanist,memsql/arcanist,eSpark/arcanist,calblueprint/arcanist,dguo-coursera/arcanist,chundongwang/arcanist,dguo-coursera/arcanist,Symplicity/arcanist,zhihu/arcanist,julkiewicz/arcanist,jra3/arcanist,zhihu/arcanist,aik099/arcanist,fivestars/arcanist,julkiewicz/arcanist,kevinseelbach/arcanist,coursera/arcanist,memsql/arcanist,codelabs-ch/arcanist,r4nt/arcanist,jra3/arcanist,sneakpeeq/arcanist,hach-que/arcanist,wikimedia/phabricator-arcanist,fivestars/arcanist,PageUpPeopleOrg/arcanist-patches,haskell-infra/arcanist,wharris/arcanist,aik099/arcanist,kevinseelbach/arcanist,aik099/arcanist,phacility/arcanist,eSpark/arcanist,chundongwang/arcanist,wikimedia/phabricator-arcanist,hach-que/arcanist,folsom-labs/arcanist,wxstars/arcanist,codelabs-ch/arcanist,julkiewicz/arcanist,wxstars/arcanist,memsql/arcanist,fivestars/arcanist,julkiewicz/arcanist,KieranHayes/arcanist,memsql/arcanist,wxstars/arcanist,sneakpeeq/arcanist,sneakpeeq/arcanist,Khan/arcanist,sneakpeeq/arcanist,Symplicity/arcanist,calblueprint/arcanist,Symplicity/arcanist,KieranHayes/arcanist,Khan/arcanist,Khan/arcanist,wxstars/arcanist,dguo-coursera/arcanist,wharris/arcanist,kevinseelbach/arcanist,phacility/arcanist,uber/arcanist,coursera/arcanist,alexmv/arcanist,hach-que/arcanist,Khan/arcanist,chundongwang/arcanist