add helper method to add ephemeral messages; also switch 'delete message' to this new method

web/react/components/post.jsx

@@ -179,7 +179,7 @@ export default class Post extends React.Component {
         }
 
         let profilePic = null;
-        if (!this.props.hideProfilePic) {
+        if (!this.props.hideProfilePic && post.user_id !== '0') {
             let src = '/api/v1/users/' + post.user_id + '/image?time=' + timestamp + '&' + utils.getSessionIndex();
             if (post.props && post.props.from_webhook && global.window.mm_config.EnablePostIconOverride === 'true') {
                 if (post.props.override_icon_url) {