Removed TLS1_2_KEY_EXCHANGES_WITH_ECDSA_CERT as it is no longer used

Signed-off-by: Ben Taylor <ben.taylor@linaro.org>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 29d0b3f..7976eec 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -314,8 +314,6 @@
 TLS1_2_KEY_EXCHANGES_WITH_CERT="MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
                                 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED"
 
-TLS1_2_KEY_EXCHANGES_WITH_ECDSA_CERT="MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED"
-
 TLS1_2_KEY_EXCHANGES_WITH_CERT_WO_ECDH="MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
                                         MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED"