travis-ci: bumped the NGINX core to 1.21.3.

Author: jiahao

.travis.yml

@@ -50,8 +50,8 @@ env:
     - DRIZZLE_VER=2011.07.21
     - TEST_NGINX_SLEEP=0.006
   jobs:
-    - NGINX_VERSION=1.19.9 OPENSSL_VER=1.1.0l OPENSSL_PATCH_VER=1.1.0d
-    - NGINX_VERSION=1.19.9 OPENSSL_VER=1.1.1l OPENSSL_PATCH_VER=1.1.1f
+    - NGINX_VERSION=1.21.3 OPENSSL_VER=1.1.0l OPENSSL_PATCH_VER=1.1.0d
+    - NGINX_VERSION=1.21.3 OPENSSL_VER=1.1.1l OPENSSL_PATCH_VER=1.1.1f
 
 services:
  - memcached