Remove s390x-linux from contbuild
Remove s390x-linux from contbuild

Currently failing cxx exception test.  Need to debug.

Blames to f1cee65e7594db55244723c418559b425297e7e1
hoever, this just exposed the problem by building the test,
it's probably been broken for a while (so a revert won't help)

vtjnash/libunwind,libunwind/libunwind,frida/libunwind,frida/libunwind,vtjnash/libunwind,libunwind/libunwind,frida/libunwind,djwatson/libunwind,djwatson/libunwind,djwatson/libunwind,vtjnash/libunwind,libunwind/libunwind