fix: email 推送事件, 缺少msg_source

src/views/Conversations/Online/Components/ChannelLogo.jsx

@@ -7,7 +7,7 @@ const ChannelLogo = ({channel}) => {
   if (Array.isArray(channel)) {
     channel = channel[channel.length - 1];
   }
-  const _channel = channel.toLowerCase();
+  const _channel = (channel || '').toLowerCase();
   switch (_channel) {
     case 'waba':
       return <WABIcon key={channel} className='text-whatsapp' />;