docs: Fix broken rpc link (#4221)
docs: Fix broken rpc link (#4221)

- chane rpc link to master branch rpc docs, current link leads to 404
- closes #4199

Signed-off-by: Marko Baricevic <d32c6d9e4f32928f8497b4e6df66c8d9233a805d@yahoo.com>
tendermint/tendermint,tendermint/tendermint,tendermint/tendermint,tendermint/tendermint