Changed error code message to also cover missing pre-shared key
diff --git a/include/polarssl/ssl.h b/include/polarssl/ssl.h
index 5c86bb3..6215ffe 100644
--- a/include/polarssl/ssl.h
+++ b/include/polarssl/ssl.h
@@ -73,7 +73,7 @@
#define POLARSSL_ERR_SSL_NO_CLIENT_CERTIFICATE -0x7480 /**< No client certification received from the client, but required by the authentication mode. */
#define POLARSSL_ERR_SSL_CERTIFICATE_TOO_LARGE -0x7500 /**< Our own certificate(s) is/are too large to send in an SSL message.*/
#define POLARSSL_ERR_SSL_CERTIFICATE_REQUIRED -0x7580 /**< The own certificate is not set, but needed by the server. */
-#define POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED -0x7600 /**< The own private key is not set, but needed. */
+#define POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED -0x7600 /**< The own private key or pre-shared key is not set, but needed. */
#define POLARSSL_ERR_SSL_CA_CHAIN_REQUIRED -0x7680 /**< No CA Chain is set, but required to operate. */
#define POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE -0x7700 /**< An unexpected message was received from our peer. */
#define POLARSSL_ERR_SSL_FATAL_ALERT_MESSAGE -0x7780 /**< A fatal alert message was received from our peer. */