Update libc crate

Cargo.lock

@@ -73,9 +73,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.126"
+version = "0.2.139"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
+checksum = "201de327520df007757c1f0adce6e827fe8562fbc28bfd9c15571c66ca1f5f79"
 
 [[package]]
 name = "opaque-debug"
@@ -131,6 +131,8 @@ dependencies = [
 [[package]]
 name = "redox-daemon"
 version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21e31c834277709c7ff3eb74959fe62be4b45b1189ba9d41fd3744cd3a9c554f"
 dependencies = [
  "libc",
  "redox_syscall",