revert: impl From<sigaction> for SigAction (#2410) #62

Job	Run time
macos	2m 56s
minver	11s
macos-aarch64	2m 0s
linux_native_builds (x86_64-unknown-linux-gnu)	2m 32s
linux_native_builds (x86_64-unknown-linux-musl)	2m 37s
rust_stable	1m 23s
rustfmt	6s
tier3 (x86_64-unknown-dragonfly)	58s
tier3 (x86_64-unknown-openbsd)	52s
tier3 (x86_64-unknown-haiku)	51s
redox	30s
cross (arm-unknown-linux-gnueabi)	1m 42s
cross_compiling (aarch64-linux-android)	30s
cross (armv7-unknown-linux-gnueabihf)	1m 38s
cross_compiling (arm-linux-androideabi)	32s
cross (i686-unknown-linux-gnu)	1m 40s
cross_compiling (armv7-linux-androideabi)	33s
cross (i686-unknown-linux-musl)	2m 6s
cross_compiling (i686-linux-android)	34s
cross (mips-unknown-linux-gnu)	1m 41s
cross_compiling (x86_64-linux-android)	34s
cross (mips64-unknown-linux-gnuabi64)	1m 43s
cross_compiling (arm-unknown-linux-musleabi)	36s
cross (mips64el-unknown-linux-gnuabi64)	1m 43s
cross_compiling (x86_64-unknown-fuchsia)	23s
cross (mipsel-unknown-linux-gnu)	1m 35s
cross_compiling (x86_64-unknown-illumos)	25s
cross (powerpc64le-unknown-linux-gnu)	1m 42s
cross_compiling (aarch64-apple-ios, true)	34s
cross_compiling (powerpc64-unknown-linux-gnu)	36s
cross_compiling (s390x-unknown-linux-gnu)	38s
cross_compiling (x86_64-unknown-linux-gnux32)	40s
cross_compiling (x86_64-unknown-netbsd)	25s
	37m 26s

Provide feedback