[baremetal] MaaS: Fix DHCP dynamic range (2)

[baremetal] MaaS: Fix DHCP dynamic range (2)

- reduce range to silence bogus MaaS warning about address exhaustion;
- regenerate pod_config.yml.example to reflect the changes;
- drop `opnfv_infra_maas_pxe_address` (duplicate of
  `opnfv_infra_maas_node01_deploy_address`);
- add `opnfv_infra_config_pxe_address` for future usage;

JIRA: FUEL-316

Change-Id: I981fc8c7c550c2917b07dd5f2c83896def013fa7
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
(cherry picked from commit 215a37d55356333f9fd0a96118c9a00d588eca62)