Remove option to send staking rewards to Controller

[laboon]

(this may be impossible without hard-coding an exception, feel free to close if so)

Right now a user can try to set the staking rewards destination to Controller, but this will always fail on-chain as controllers are deprecated and you can't set it to Controller. So this option on PJS App (for Polkadot and Kusama) will always fail. If possible, it would make sense to remove it or not display it to the user.