Clean unrelated multisig accounts

Context

There was a bug introduced in 0.9.3. that was showing unrelated multisig contracts on a page. Even though this has been fixed, if a user open the 0.9.3 version it would store all these multisigs in their local storage and it wouldn't go away after the refresh. The simplest solution is to remove this particular cache entry and it will be replaced with proper values on the next refresh cycle