Previously, handshake timeouts were recorded as generic peer errors
instead of timeout errors. waitForHandshake passed a raw
p2p.DiscReadTimeout into markError, but markError classified errors only
via errors.Unwrap(err), which returns nil for non-wrapped errors. As a
result, the timeoutError meter was never incremented and all such
failures fell into the peerError bucket.
This change makes markError switch on the base error, using
errors.Unwrap(err) when available and falling back to the original error
otherwise. With this adjustment, p2p.DiscReadTimeout is correctly mapped
to timeoutError, while existing behaviour for the other wrapped sentinel
errors remains unchanged
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Co-authored-by: lightclient <lightclient@protonmail.com>