Fuzzy test

[ineiti]

Here is one more fuzzy test, this time from the minows module:

./mino/minows/session_test.go:Test_session_Recv_SessionEnded

It is difficult to reproduce on my computer, only one out of 10'000 runs produces the error. On github it's much more prevalent, nearly every time it is triggered.

If it runs on its own in the Makefile:test, it seems to be better.