fixup! Tests: alternative chains support.

Author: bavshin-f5

t/acme_alternative_chains.t renamed to t/acme_preferred_chain.t

@@ -5,7 +5,7 @@
 # This source code is licensed under the Apache License, Version 2.0 license
 # found in the LICENSE file in the root directory of this source tree.
 
-# Tests for ACME client: alternative certificate chains.
+# Tests for ACME client: preferred chain support.
 
 ###############################################################################
 
@@ -54,15 +54,15 @@ http {
 
     acme_issuer chain1 {
         uri https://acme.test:%%PORT_9000%%/dir;
-        chain "issuer=%%ISSUER_NAME_1%%";
+        preferred_chain "%%ISSUER_NAME_1%%";
         ssl_trusted_certificate acme.test.crt;
         state_path %%TESTDIR%%/acme_chain1;
         accept_terms_of_service;
     }
 
     acme_issuer chain2 {
         uri https://acme.test:%%PORT_9000%%/dir;
-        chain "issuer=%%ISSUER_NAME_2%%";
+        preferred_chain "%%ISSUER_NAME_2%%";
         ssl_trusted_certificate acme.test.crt;
         state_path %%TESTDIR%%/acme_chain2;
         accept_terms_of_service;