witness_node program now can be used to serve the features that was served by
witness_node as a delayed node, some options are required to be configured appropriately.
1. Disable P2P connection
witness_node with command line option
--p2p-endpoint=127.0.0.1:0, or configure the options in
p2p-endpoint = 127.0.0.1:0 seed-nodes = 
2. Enable delayed_node plugin
--plugins="delayed_node [and other required plugins]", or configure it in
plugins = delayed_node
3. Fetch blocks from a trusted witness node via RPC
--trusted-node="ip.address.of.the.witness.node:rpc-port", or configure it in
trusted-node = ip.address.of.the.witness.node:rpc-port
Assuming the RPC endpoint of the trusted node is
127.0.0.1:8090, we can have following options in
config.ini of a delayed node.
p2p-endpoint = 127.0.0.1:0 seed-nodes =  plugins = delayed_node account_history api_helper_indexes trusted-node = 127.0.0.1:8090