updated default observer definitions

in order to be compatible with the latest concordia version modified in ac38d0dfc4c16809f7587f8677282806464159f9. @joshuaselsky -- could you take a look at this and merge if you agree that it resolves the issue? currently, someone setting up a ohmage server with the latest master/2.16 commit and the db scripts would create definitions not compatible with the concordia version in use.