PLT-1380: Post system message when user updates channel header

web/react/components/post.jsx

@@ -152,7 +152,7 @@ export default class Post extends React.Component {
         }
 
         let currentUserCss = '';
-        if (UserStore.getCurrentId() === post.user_id && !post.props.from_webhook) {
+        if (UserStore.getCurrentId() === post.user_id && !post.props.from_webhook && !utils.isSystemMessage(post)) {
             currentUserCss = 'current--user';
         }