Close connections to nodes not returned by address provider

[akudiyar]

Currently, the existing connections to the addresses that were not returned by the address provider during the next connection sequence, are not closed after establishing new connections, although new requests will not be dispatched to them. If such connections will not be closed by the server, they may stay alive for a long time and affect the client resources.

These "old" connections must be closed after the new ones are established if they are not already closed by a disconnect event.

[vrogach2020]

@wey1and seems to be fixed by
#167

Can we close it ?

[vrogach2020]

@wey1and need research, please test this case