Update Discord link to a permanent invite

Author: essen

README.asciidoc

@@ -33,6 +33,6 @@ to close any of the currently opened sockets.
 
 == Getting help
 
-* https://discord.gg/x468ZsxG[Discord server]
+* https://discord.gg/x25nNq2fFE[Discord server]
 * https://github.com/ninenines/ranch/issues[Issues tracker]
 * https://ninenines.eu/services[Commercial Support]