Add a test that declining ALPN works.

Inspired by https://mta.openssl.org/pipermail/openssl-dev/2016-March/006150.html

Change-Id: I973b3baf054ed1051002f7bb9941cb1deeb36d78
Reviewed-on: https://boringssl-review.googlesource.com/7504
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/ssl/test/test_config.cc b/ssl/test/test_config.cc
index dfbd380..67a017d 100644
--- a/ssl/test/test_config.cc
+++ b/ssl/test/test_config.cc
@@ -62,6 +62,7 @@
   { "-no-ssl3", &TestConfig::no_ssl3 },
   { "-shim-writes-first", &TestConfig::shim_writes_first },
   { "-expect-session-miss", &TestConfig::expect_session_miss },
+  { "-decline-alpn", &TestConfig::decline_alpn },
   { "-expect-extended-master-secret",
     &TestConfig::expect_extended_master_secret },
   { "-enable-ocsp-stapling", &TestConfig::enable_ocsp_stapling },