## Issue Addressed
The fee-recipient argument of the beacon node does not allow a value to be specified:
> $ lighthouse beacon_node --merge --fee-recipient "0x332E43696A505EF45b9319973785F837ce5267b9"
> error: Found argument '0x332E43696A505EF45b9319973785F837ce5267b9' which wasn't expected, or isn't valid in this context
>
> USAGE:
> lighthouse beacon_node --fee-recipient --merge
>
> For more information try --help
## Proposed Changes
Allow specifying a value for the fee-recipient argument in beacon_node/src/cli.rs
## Additional Info
I've added .takes_value(true) and successfully proposed a block in the kintsugi testnet with my own fee-recipient address instead of the hardcoded default. I think that was just missed as the argument does not make sense without a value :)
Co-authored-by: pk910 <philipp@pk910.de>
Co-authored-by: Michael Sproul <micsproul@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>