Bump socket2 from 0.3.12 to 0.3.19 in /examples/signaling-server-rust

Bumps [socket2](https://github.com/rust-lang/socket2) from 0.3.12 to 0.3.19.
- [Release notes](https://github.com/rust-lang/socket2/releases)
- [Changelog](https://github.com/rust-lang/socket2/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-lang/socket2/compare/0.3.12...v0.3.19)

---
updated-dependencies:
- dependency-name: socket2
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

examples/signaling-server-rust/Cargo.lock

@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "arc-swap"
 version = "0.4.7"
@@ -75,6 +77,12 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "core-foundation"
 version = "0.7.0"
@@ -253,7 +261,7 @@ version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7abc8dd8451921606d809ba32e95b6111925cd2906060d2dcc29c070220503eb"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "wasi",
 ]
@@ -365,7 +373,7 @@ version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
 ]
 
 [[package]]
@@ -386,7 +394,7 @@ version = "0.6.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fce347092656428bc8eaf6201042cb551b8d67855af7374542a92a0fbfcac430"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "fuchsia-zircon",
  "fuchsia-zircon-sys",
  "iovec",
@@ -468,7 +476,7 @@ version = "0.2.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2ba7c918ac76704fb42afcbbb43891e72731f3dcca3bef2a19786297baf14af7"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "winapi 0.3.9",
 ]
@@ -502,7 +510,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8d575eff3665419f9b83678ff2815858ad9d11567e082f5ac1814baba4e2bcb4"
 dependencies = [
  "bitflags",
- "cfg-if",
+ "cfg-if 0.1.10",
  "foreign-types",
  "lazy_static",
  "libc",
@@ -727,13 +735,12 @@ checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 
 [[package]]
 name = "socket2"
-version = "0.3.12"
+version = "0.3.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "03088793f677dce356f3ccc2edb1b314ad191ab702a5de3faf49304f7e104918"
+checksum = "122e570113d28d773067fab24266b66753f6ea915758651696b6e35e49f88d6e"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
  "libc",
- "redox_syscall",
  "winapi 0.3.9",
 ]
 
@@ -754,7 +761,7 @@ version = "3.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "rand",
  "redox_syscall",