RUSTSEC-2020-0016: net2 crate has been deprecated; use socket2 instead

[github-actions]

net2 crate has been deprecated; use socket2 instead

Details
Status	unmaintained
Package	net2
Version	0.2.37
URL	deprecrated/net2-rs@3350e38
Date	2020-05-01

The net2 crate has been deprecated
and users are encouraged to considered socket2 instead.

See advisory page for additional details.

[ssalonen]

net2 comes from old tokio that is still used by hyper :

$ cargo tree --invert -p net2                                                                                                                                 master ✭ ✱
net2 v0.2.37
└── mio v0.6.23
    └── tokio v0.2.24
        ├── h2 v0.2.7
        │   └── hyper v0.13.9
        │       ├── hyper-tls v0.4.3
        │       │   └── webcam-proxy v0.1.2 (/home/salski/src/webcam-proxy)
        │       └── webcam-proxy v0.1.2 (/home/salski/src/webcam-proxy)
        ├── hyper v0.13.9 (*)
        ├── hyper-tls v0.4.3 (*)
        ├── tokio-compat-02 v0.1.2
        │   └── webcam-proxy v0.1.2 (/home/salski/src/webcam-proxy)
        ├── tokio-tls v0.3.1
        │   └── hyper-tls v0.4.3 (*)
        └── tokio-util v0.3.1
            └── h2 v0.2.7 (*)

Hyper 0.14 should land with the tokio 0.3: hyperium/hyper#2302

At the same time we can drop the tokio-compat-02.

[ssalonen]

See dd4468f. No longer depending on net2