Fix fail_second_ddos_callback flag.

It was failing only on 32-bit for some reason. Part of TestConfig wasn't
getting initialized.

Change-Id: I2a3747a347a47b47e2357f34d32f8db86d6cc629
Reviewed-on: https://boringssl-review.googlesource.com/4110
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/test_config.cc b/ssl/test/test_config.cc
index 1f7bd5b..2bee978 100644
--- a/ssl/test/test_config.cc
+++ b/ssl/test/test_config.cc
@@ -148,7 +148,8 @@
       use_early_callback(false),
       fail_early_callback(false),
       install_ddos_callback(false),
-      fail_ddos_callback(false) {
+      fail_ddos_callback(false),
+      fail_second_ddos_callback(false) {
 }
 
 bool ParseConfig(int argc, char **argv, TestConfig *out_config) {