Fix a few more #ifdef's
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 0a8119e..6918e4b 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -6578,7 +6578,7 @@
     }
 #endif
 
-#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+#if defined(MBEDTLS_X509_CRT_PARSE_C)
     if( ssl->hostname != NULL )
     {
         mbedtls_zeroize( ssl->hostname, strlen( ssl->hostname ) );