Reset away status on ICB [irssi/tmux_away.pl]

The tmux_away script for irssi properly sets the away status and away message.
This works on IRC networks as well as on networks that are joined via the ICB
module.

When attaching to the tmux terminal, the away status is reset on IRC networks.
The away status on the ICB networks is _not_ reset. This diff for the tmux_away
plugin fixes this.

--- ../tmux_away.pl	Wed Nov 18 08:34:26 2020
+++ tmux_away.pl	Sun Aug  1 13:19:07 2021
@@ -180,6 +180,9 @@
           $_->command("NICK " . $old_nicks{$_->{'tag'}});
           $old_nicks{$_->{'tag'}} = "";
         }
+        if ($_->{chat_type} eq 'ICB') {
+            $_->command("QUOTE noaway");
+        }
       }
       $away_status = $status;
     } elsif ($immediate) {