Fabrice Bellet authored Jun 07, 2016 and Olivier Crête committed Jun 20, 2016

This patch reworks commit fc4d3aab "ignore gathering failures on
auto-generated IPs", that introduces a regression in the test-fullmode
check, when turn is on and use_loopback is off. The part of the test
that fails is when nice_agent_gather_candidates (ragent...) should
return false when the port range for the second component is already
busy, line 385.

In this case, agent->local_address is null, so the code path added by
commit fc4d3aab is taken, and the function will return true, even when
not local address has been gathered.

The proper fix is to swap the inner and outer loops (on components, and
on local addresses), and to go to error when all local addresses of a
given component have failed, and to return false only in this case.