Fixes React.js console errors (#7829)

src/components/views/elements/GenericEventListSummary.tsx

@@ -70,7 +70,9 @@ const GenericEventListSummary: React.FC<IProps> = ({
     if (events.length < threshold) {
         return (
             <li className="mx_GenericEventListSummary" data-scroll-tokens={eventIds} data-expanded={true} data-layout={layout}>
-                { children }
+                <ol className="mx_GenericEventListSummary_unstyledList">
+                    { children }
+                </ol>
             </li>
         );
     }

src/components/views/rooms/EventTile.tsx

@@ -1362,6 +1362,7 @@ export default class EventTile extends React.Component<IProps, IState> {
             reactionsRow = <ReactionsRow
                 mxEvent={this.props.mxEvent}
                 reactions={this.state.reactions}
+                key="mx_EventTile_reactionsRow"
             />;
         }