lwip: Merge upstream commit "tcp: Avoid 3-second delay for a half-open connection"
lwip: Merge upstream commit "tcp: Avoid 3-second delay for a half-open connection"

Upstream commit: 2e26fc9224b019f5630258c0198cd0148766cb82

johnkingsley/aprinter,ambrop72/aprinter,johnkingsley/aprinter,ambrop72/aprinter,ambrop72/aprinter,ambrop72/aprinter,johnkingsley/aprinter,johnkingsley/aprinter,johnkingsley/aprinter,ambrop72/aprinter,johnkingsley/aprinter,ambrop72/aprinter,ambrop72/aprinter,johnkingsley/aprinter