Incorrect Cw4ExecuteMsg used during remove_hook

[sushiwushi]

Quoting from https://github.com/CosmWasm/cw-plus/blob/main/packages/cw4/src/helpers.rs#L45-L48:

pub fn remove_hook<T: Into<String>>(&self, addr: T) -> StdResult<CosmosMsg> {
        let msg = Cw4ExecuteMsg::AddHook { addr: addr.into() }; //uses AddHook instead of RemoveHook
        self.encode_msg(msg)
    }

Probably should be:

pub fn remove_hook<T: Into<String>>(&self, addr: T) -> StdResult<CosmosMsg> {
        let msg = Cw4ExecuteMsg::RemoveHook { addr: addr.into() };
        self.encode_msg(msg)
    }

PS: This was found during an audit.

[maurolacy]

Thanks, we'll fix it asap.