Fix a delete type mismatch (deleting a sockaddr_in6* as a sockaddr*)
Fix a delete type mismatch (deleting a sockaddr_in6* as a sockaddr*)

This triggered ASan, saying "object passed to delete has wrong type".
This error is caused by allocating a `struct sockaddr_in6`, casting it
and deleting it as `struct sockaddr*` which has a smaller size.

BUG=None

Review-Url: https://codereview.webrtc.org/2999053002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#19401}

TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc