Increase PHP opcache.interned_strings_buffer for Nextcloud

Some Nextcloud installations are complaining, so let's increase it for
everyone.

profile/manifests/nextcloud.pp

@@ -36,7 +36,7 @@ class profile::nextcloud (
       # a sane parameter here. For details, see:
       # https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/config_sample_php_parameters.html#user-experience
       'Session/session.gc_maxlifetime'          => 2 * $session_lifetime,
-      'opcache/opcache.interned_strings_buffer' => 16,
+      'opcache/opcache.interned_strings_buffer' => 32,
       'opcache/opcache.memory_consumption'      => 256,
     },
     cli_settings => {