message_list_view: Remove duplicate comment.

The comment and the conditional check is already present at the
start of the function.

This seems to have been introduced in
a9235a74f4, back in 2014.

static/js/message_list_view.js

@@ -629,10 +629,7 @@ export class MessageListView {
             }
         };
 
-        // This function processes messages into chunks with separators between them,
-        // and templates them to be inserted as table rows into the DOM.
-
-        if (message_containers.length === 0 || this.table_name === undefined) {
+        if (message_containers.length === 0) {
             return undefined;
         }