mulitsig example contract: can not call `add_owner`, `remove_owner`, `replace_owner`

[achimcc]

Whenever I try to invoke any of the functions add_owner, remove_owner, replace_owner of the multisig ink! contract from the examples folder, I receive the following error:

ERROR: Module error: Contracts: ContractTrapped

Contract trapped during execution.

I did test it with apps, contracts ui and cargo-contract with:

cargo-contract 0.17.0-c6f9de0-x86_64-linux-gnu ink! 3.0.0-rc9 substrate-contracts-node 0.8.0-382b446-x86_64-linux-gnu

Also not successfull with canvas on rococco.

I also checked that they are currently not tested by ink! waterfall, I'd suggest to add tests for them.