readme: update discord invite (#458)

* readme: update discord invite

* readme: update discord invite

README.md

@@ -1,5 +1,5 @@
 # Xash3D FWGS Engine
-[![Build Status](https://api.travis-ci.org/FWGS/xash3d-fwgs.svg?branch=master)](https://travis-ci.org/FWGS/xash3d-fwgs) [![FreeBSD Build Status](https://img.shields.io/cirrus/github/FWGS/xash3d-fwgs?label=freebsd%20build)](https://cirrus-ci.com/github/FWGS/xash3d-fwgs) [![Discord Server](https://img.shields.io/discord/355697768582610945.svg)](https://discord.gg/TbnHcVb) \
+[![Build Status](https://api.travis-ci.org/FWGS/xash3d-fwgs.svg?branch=master)](https://travis-ci.org/FWGS/xash3d-fwgs) [![FreeBSD Build Status](https://img.shields.io/cirrus/github/FWGS/xash3d-fwgs?label=freebsd%20build)](https://cirrus-ci.com/github/FWGS/xash3d-fwgs) [![Discord Server](https://img.shields.io/discord/355697768582610945.svg)](http://discord.fwgs.ru/) \
 [![Download Stable](https://img.shields.io/badge/download-stable-yellow)](https://github.com/FWGS/xash3d-fwgs/releases/latest) [![Download Testing](https://img.shields.io/badge/downloads-testing-orange)](https://github.com/FWGS/xash3d-deploy/tree/anewengine-master)
 
 Xash3D FWGS is a fork of Xash3D Engine by Unkle Mike with extended features and crossplatform.