curl: 29: CURLOPT_ISSUERCERT accepts a different-key certificate when issuer metadata collides

Summary osslcheckissuer in lib/vtls/openssl.c uses X509checkissued to implement CURLOPTISSUERCERT. This OpenSSL function checks metadata subject/issuer names, key identifiers, algorithm compatibility, key usage but does not verify the certificate's cryptographic signature. A certificate with...