Remove libera.chat as a default since their rooms are not accessible …

…in the archive (#263)

The history visibility in Libera rooms is set to `join` which means it's not
accessible in the archive at all. Instead of leading a bunch of people to
`403 Forbidden`, we can just remove it from the default list.

The default list was mostly just copied from the Element list of defaults.

shared/viewmodels/RoomDirectoryViewModel.js

@@ -10,7 +10,7 @@ const HomeserverSelectionModalContentViewModel = require('matrix-public-archive-
 const RoomCardViewModel = require('matrix-public-archive-shared/viewmodels/RoomCardViewModel');
 const checkTextForNsfw = require('matrix-public-archive-shared/lib/check-text-for-nsfw');
 
-const DEFAULT_SERVER_LIST = ['matrix.org', 'gitter.im', 'libera.chat'];
+const DEFAULT_SERVER_LIST = ['matrix.org', 'gitter.im'];
 
 class RoomDirectoryViewModel extends ViewModel {
   constructor(options) {