Add RSK (Rootstock) support

[gofman8]

Hello,
Could it be possible to add RSK network support ?
https://github.com/rsksmart/rskj

https://github.com/emeraldpay/dshackle/blob/master/proto/common.proto#L22

Thanks in advince!

[taxmeifyoucan]

If you don't need a first class support and want just to make it work now, you can use a workaround by disabling chain validation. It should work with probably any EVM chain. Here is an example for Ethereum L2 https://github.com/taxmeifyoucan/eth-rpc-proxy/blob/master/dshackle_conf/arbitrum.yaml