Implements a Proxy Integration

[Bart1909]

Now, you can use HTTP or SOCKS5 proxies with this bot.
In config.yaml under telegram add the two following lines:
http_proxy: http://user:pass@proxy.com:3128
https_proxy: http://user:pass@proxy.com:3128

If you are using SOCKS5 proxy, the lines looks like this:
http_proxy: socks5://user:pass@proxy.com:3128
https_proxy: socks5://user:pass@proxy.com:3128

Maybe you have to run the following line to install socks-compability:
pip install requests[socks]

[NickRimmer]

Hey! When I tried this "pip install requests[socks]", I got this )=

platformio 3.3.1 has requirement click<6,>=5, but you'll have click 6.7 which is incompatible.
octoprint 1.3.6 has requirement Click<6.3,>=6.2, but you'll have click 6.7 which is incompatible.
octoprint 1.3.6 has requirement pyserial<2.8,>=2.7, but you'll have pyserial 3.3 which is incompatible.
octoprint 1.3.6 has requirement requests<3,>=2.18.4, but you'll have requests 2. 17.3 which is incompatible.
octoprint 1.3.6 has requirement semantic_version<2.5,>=2.4.2, but you'll have se mantic-version 2.6.0 which is incompatible.

[NickRimmer]

Without installation socks-compability, I have error in Telegram-Octoprint plugin page:

Got an exception while initially trying to connect to telegram (Listener not running: Missing dependencies for SOCKS support.. Waiting 2 minutes before trying again.)