New messages in disabled channels are still displayed
Reproduce with 2 characters:
- Character A does
/join testchannel
- Character B does
/join testchannel
- Character B sends a message in
$testchannel
- Message is shown on A (correct behavior)
- Character A clicks the filter button to hide the channel
- Message is now hidden on A (correct behavior)
- Character B sends another message in the channel
- Message is shown on A even though the channel is hidden (incorrect)