[fix] Remove new openvpn service override file

scripts/remove

@@ -68,7 +68,7 @@ ynh_secure_remove /etc/openvpn/client.conf.tpl
 ynh_secure_remove /etc/yunohost/hooks.d/90-vpnclient.tpl
 
 # Remove openvpn service
-ynh_secure_remove /etc/systemd/system/openvpn@.service
+ynh_secure_remove /etc/systemd/system/openvpn@.service.d/override.conf
 
 # Remove openvpn certificates
 ynh_secure_remove /etc/openvpn/keys