rpc: Ignore and log errors during cancel
rpc: Ignore and log errors during cancel

Cancelling the RPC acceptors can sometimes result in an error about
a bad file descriptor.

As this is the shutdown sequence we need to continue nevertheless,
ignore these errors, log a warning and proceed.

Fixes #4352.

(cherry picked from commit 33e5b4291036bbdad075f4a549491af72d8a0618)

reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin