test/TEST-12-ISSUE-3171: specify -w1 option to netcat due to default change. (#5722)

On Ubuntu 17.04 (zesty zapus) netcat-openbsd was upgraded from 1.105-7ubuntu1
to 1.130-3, at the same time the defaults got changed from -q0 to -q-1
(infinity) the net result is that `echo A | nc -U' call now hangs, preventing
the testcase to complete. One could use the old default of -q0, but that option
is not available in some netcat implementations. Thus settle to specify -w1
instead to mitigate the testcase hang.