Fix candidates memory leaks

[fancycode]

• Ignored peer-reflexive candidates were not released.
• All found local candidates after the one that was used were leaking.

[lminiero]

Good catch, I thought nice_agent_get_local_candidates only allocated the list, but looking at the documentation it looks like the caller owns the candidate objects too. I wonder if this changed recently, though? I wouldn't want this to crash instances with older versions of libnice.

[fancycode]

I don't think this is something new in libnice, most of the candidates returned by nice_agent_get_local_candidates were already freed in the existing code, e.g. here:

janus-gateway/ice.c

Line 2047 in 3498214

nice_candidate_free(c);

janus-gateway/ice.c

Line 3658 in 3498214

nice_candidate_free(c);

[lminiero]

Ack, makes sense, merging then! Thanks 👍