Don't reset room state if join is in progress

This is an attempt at resolving OMEMO decryption issues in groups for some
users.

Snikket/groupchat/MucChatOccupantsTableViewController.swift

@@ -332,7 +332,7 @@ class MucChatOccupantsTableViewController: UITableViewController {
             return;
         }
         
-        if room.state != .joined {
+        if room.state != .joined && room.state != .requested {
             DispatchQueue.main.async {
                 self.members.removeAll()
                 self.tableView?.reloadData();