Revert "lwip: fixed bug #48170 (patch by Fabian Koch)"
Revert "lwip: fixed bug #48170 (patch by Fabian Koch)"

This reverts commit c2292c23bde00c2d0604608fd32776cf81c4ae2f.

Reverted due to causing a serious DOS condition after a client closes connection.
Bug reported upstream: https://savannah.nongnu.org/bugs/?48328

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