nextcloud: Fetch HTTPS cert from Kubernetes

Since Nextcloud uses the _pyrocufflink.net_ wildcard certificate, we can
load it directly from the Kubernetes Secret, rather than from the file
in the _certs_ submodule, just like Gitea et al.

roles/nextcloud/meta/main.yml

@@ -3,11 +3,3 @@ dependencies:
 - role: redis
   tags:
   - redis
-- role: cert
-  vars:
-    cert_src: lego/_.pyrocufflink.net.crt
-    cert_dest: '{{ apache_ssl_certificate }}'
-    cert_key_src: lego/_.pyrocufflink.net.key
-    cert_key_dest: '{{ apache_ssl_certificate_key }}'
-  tags:
-  - nextcloud