re-introduce nginx custom default values
re-introduce nginx custom default values

3b676b5a56 added some nginx custom variables. A few of them were
removed in the Juniper upgrade but `nginx_lms_client_max_body_size`
and `nginx_lms_proxy_read_timeout` are still used in the
`lms-common-settings.j2` template, leading to a
`AnsibleUndefinedVariable` if that part of the template gets executed.

appsembler/configuration,appsembler/configuration,appsembler/configuration,appsembler/configuration