Remove the Twitch Channel when closing the split

src/widgets/split.cpp

@@ -317,6 +317,7 @@ void Split::doAddSplit()
 void Split::doCloseSplit()
 {
     SplitContainer *page = static_cast<SplitContainer *>(this->parentWidget());
+    singletons::ChannelManager::getInstance().removeTwitchChannel(this->channel->name);
     page->removeFromLayout(this);
 }