Fix build break.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
diff --git a/apps/apps.h b/apps/apps.h
index f2dc812..99c5809 100644
--- a/apps/apps.h
+++ b/apps/apps.h
@@ -450,7 +450,7 @@
 OCSP_RESPONSE *process_responder(OCSP_REQUEST *req,
                                  const char *host, const char *path,
                                  const char *port, int use_ssl,
-                                 const STACK_OF(CONF_VALUE) *headers,
+                                 STACK_OF(CONF_VALUE) *headers,
                                  int req_timeout);
 # endif
 
diff --git a/apps/ocsp.c b/apps/ocsp.c
index 5b3092a..7193dae 100644
--- a/apps/ocsp.c
+++ b/apps/ocsp.c
@@ -1256,7 +1256,7 @@
 OCSP_RESPONSE *process_responder(OCSP_REQUEST *req,
                                  const char *host, const char *path,
                                  const char *port, int use_ssl,
-                                 const STACK_OF(CONF_VALUE) *headers,
+                                 STACK_OF(CONF_VALUE) *headers,
                                  int req_timeout)
 {
     BIO *cbio = NULL;