(net.Error).Temporary is deprecated

[slingamn]

https://pkg.go.dev/net#Error

See if we should reevaluate:

ergo/irc/utils/proxy.go

Lines 23 to 37 in f3e24c7

	// XXX implement net.Error with a Temporary() method that returns true;
	// otherwise, ErrBadProxyLine will cause (*http.Server).Serve() to exit
	type proxyLineError struct{}
	func (p *proxyLineError) Error() string {
	return "invalid PROXY line"
	}
	func (p *proxyLineError) Timeout() bool {
	return false
	}
	func (p *proxyLineError) Temporary() bool {
	return true
	}