* better error

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <[email protected]>

* remove unused

* fix error

* fmt

* fix tests

* fmt

* Update frame/contracts/src/exec.rs

Co-authored-by: Alexander Theißen <[email protected]>

* fix typo

Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Alexander Theißen <[email protected]>