mgcp_client_pool: add mgcp_client_pool_empty()

Check if the private struct mgcp_client_pool has an empty member_list.

Clients that support both the legacy config and the pool config can
use this to properly exit with error if pool members are configured,
but no connection to any of the pool members can be established.

Currently clients can't distinguish a config without pool members and a
config with pool members that is broken and will fall back to using the
defaults of the legacy config in both cases.

Related: OS#5993
Change-Id: I009483ac9dfd6627e414f14d43b89f40ea4644db
2 files changed