Clean the last remnant of ISC_PLATFORM_HAVEIPV6 macro
In set_sndbuf() we were using ISC_PLATFORM_HAVEIPV6 macro that doesn't exist anymore, because we assume that IPv6 support is always available.
(cherry picked from commit 96ac91a1)
In set_sndbuf() we were using ISC_PLATFORM_HAVEIPV6 macro that doesn't exist anymore, because we assume that IPv6 support is always available.
(cherry picked from commit 96ac91a1)