Don't accept “SSL client” as a substitute for S/MIME in the Netscape cert type extension.

I believe that case was the only way that X509_check_purpose could
return anything other than zero or one. Thus eliminate the last use of
X509_V_FLAG_X509_STRICT.

Bug: 111893041
Test: cts -m CtsLibcoreTestCases
Merged-In: I47a45e6b6f46b19fcbcb6c917895867d56dcd2ca
Change-Id: I0a937a284af0368dae14dcd5687af8a24db2a363
3 files changed