Added Socket::set_multicast_if_v4_n to set interface by index (#458) #1358

Job	Run time
Test (nightly)	24s
Test (stable)	16s
Test (1.70.0)	25s
Rustfmt	8s
Test (beta)	24s
Test (windows)	1m 59s
Test (macos)	16s
Clippy	10s
check-external-types (ubuntu-latest)	18s
check-external-types (windows-latest)	43s
check-external-types (macos-latest)	21s
Check (aarch64-apple-watchos)	32s
Check (aarch64-apple-darwin)	33s
Check (aarch64-apple-ios)	32s
Check (aarch64-apple-tvos)	35s
Check (aarch64-unknown-netbsd)	32s
Check (aarch64-unknown-linux-gnu)	35s
Check (aarch64-unknown-linux-ohos)	33s
Check (aarch64-unknown-linux-musl)	31s
Check (i686-unknown-linux-gnu)	35s
Check (sparcv9-sun-solaris)	33s
Check (armv7-unknown-linux-ohos)	31s
Check (aarch64-unknown-redox)	36s
Check (armv7-sony-vita-newlibeabihf)	34s
Check (x86_64-apple-darwin)	34s
Check (aarch64-linux-android)	33s
Check (i686-linux-android)	33s
Check (x86_64-unknown-freebsd)	37s
Check (aarch64-unknown-openbsd)	31s
Check (arm64_32-apple-watchos)	34s
Check (x86_64-pc-cygwin)	32s
Check (x86_64-unknown-linux-musl)	35s
Check (x86_64-unknown-linux-gnu)	34s
Check (aarch64-unknown-freebsd)	45s
Check (x86_64-unknown-fuchsia)	33s
Check (x86_64-unknown-illumos)	33s
Check (x86_64-unknown-redox)	32s
Check (x86_64-pc-windows-msvc)	31s
Check (armv7-linux-androideabi)	34s
Check (arm-linux-androideabi)	34s
Check (x86_64-apple-ios)	35s
Check (x86_64-unknown-netbsd)	32s
Check (x86_64-pc-solaris)	35s
Check (x86_64-unknown-openbsd)	33s
Check (x86_64-unknown-dragonfly)	32s
Check (x86_64-unknown-linux-ohos)	33s
	25m 1s

Provide feedback