Fix check for OpenSSL supported curves

OpenSSL 3.X outputs a different error message than previous versions when $OPENSSL s_client -curves X ... is called with an unsupported curve. This was resulting in the check within find_openssl_binary() adding every curve to $OPENSSL_SUPPORTED_CURVES, even ones that were not supported. This commit changes to check in order to detect the new error message.

Author: David Cooper

testssl.sh

@@ -17295,7 +17295,7 @@ find_openssl_binary() {
           HAS_CURVES=true
           for curve in "${curves_ossl[@]}"; do
                # Same as above, we just don't need a port for invalid.
-               $OPENSSL s_client -curves $curve -connect $NXCONNECT </dev/null 2>&1 | grep -Eiaq "Error with command|unknown option"
+               $OPENSSL s_client -curves $curve -connect $NXCONNECT </dev/null 2>&1 | grep -Eiaq "Error with command|unknown option|Call to SSL_CONF_cmd(.*) failed"
                [[ $? -ne 0 ]] && OSSL_SUPPORTED_CURVES+=" $curve "
           done
      fi