netbase: Do not print an error on connection timeouts through proxy

Summary:
netbase: Make InterruptibleRecv return an error code instead of bool

netbase: Do not print an error on connection timeouts through proxy

If a timeout happens while reading the proxy response, this effectively
means we timed out while connecting to the remote node. This is very
common for Tor, so do not print an error message.

This is a backport of Core PR9726

Test Plan:

make check

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Subscribers: jasonbcox, teamcity

Differential Revision: https://reviews.bitcoinabc.org/D1872