Duplicate node entries being added to pool

[Pranav0210]

When a new node is added to the pool of the running bcoin node repetitively, each "addnode add" command pushes the hostname to the pool.hosts.nodes[] without verifiying if it already exists in the array and duplicates are created as shown in the output below.

However, on running get peerinfo, the redundant entries cannot be seen because the logic provides for checking if a peer already exists in the array.