Revert "Change thread test to use fake tcp with same structure"
Revert "Change thread test to use fake tcp with same structure"

This reverts commit d39780a130923b59169f0f6fe7b046b7ba73b6cf.

Matthew says this test is really about TCP, so it should not be
changed. Although perhaps we can use a more basic TCP test to check if
this should be done.

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket