Websocket proxy

[johartl]

Sorry, yet another websocket proxy fix :/ The old proxy middleware we were using did not properly support websockets.
I tested this change with PokeMap-2 and the websocket connection was established successfully. For PokeMap-1 the websocket connection is still not working due to PokemonGoers/PokeMap-1#42.

[WoH]

G2G

[sacdallago]

Sorry :D yesterday I stopped before publishing the websocket port via nginx as I was having issues on other things and wanted to go step by step.. It's very strange that it works.. VERY strange.. My assumption is that it doesn't make use of the env var I pass it on when building, but now with longer logging I might have time to look into it

[johartl]

My assumption is that it doesn't make use of the env var I pass it on when building

That makes sense as the websocket env variable defaults to the old docker container (which is working just fine) .
The bug I fixed with this PR, however, had nothing to do with the setup of the production system. I exclusively tested it with the old docker container so this is something we would've needed to fix anyway ;)