upgrade to nginx 1.21.1 (#5152)

Author: dgrove-oss

ansible/group_vars/all

@@ -232,7 +232,7 @@ nginx:
   htmldir: "{{ ui_path | default(false) }}"
   dir:
     become: "{{ nginx_dir_become | default(false) }}"
-  version: "{{ nginx_version | default('1.19') }}"
+  version: "{{ nginx_version | default('1.21.1') }}"
   port:
     http: 80
     https: 443