Disable 02-test_errstr.t on msys/mingw as well as MSWin32

There is too high a risk that perl and OpenSSL are linked with
different C RTLs, and thereby get different messages for even the most
mundane error numbers.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8343)