Support wasm32-wasi compilation target - fix net2 dependency

This is not directly related with this crate's source code, rather some dependencies.

Though when compiling to WASI for instance there are lots of errors from `net2` which should be fixable as os::wasi has implementation for missing values/methods:

```
error[E0425]: cannot find value `SOL_SOCKET` in this scope
--> /Users/max/.cargo/registry/src/github.com-1ecc6299db9ec823/net2-0.2.33/src/ext.rs:993:33
|
993 | get_opt(self.as_sock(), SOL_SOCKET, SO_BROADCAST)
| ^^^^^^^^^^ not found in this scope
```