Change ssl_set_psk() to act on ssl_config
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 12614c1..f4c206e 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -1705,7 +1705,7 @@
 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
     if( strlen( opt.psk ) != 0 && strlen( opt.psk_identity ) != 0 )
     {
-        ret = mbedtls_ssl_set_psk( &ssl, psk, psk_len,
+        ret = mbedtls_ssl_set_psk( &conf, psk, psk_len,
                            (const unsigned char *) opt.psk_identity,
                            strlen( opt.psk_identity ) );
         if( ret != 0 )