[Glitch] Fix scroll to top in single column UI

Port 2dee293c4c to glitch-soc

Signed-off-by: Thibaut Girka <thib@sitedethib.com>

app/javascript/flavours/glitch/features/notifications/index.js

@@ -234,6 +234,7 @@ class Notifications extends React.PureComponent {
 
     return (
       <Column
+        bindToDocument={!multiColumn}
         ref={this.setColumnRef}
         name='notifications'
         extraClasses={this.props.notifCleaningActive ? 'notif-cleaning' : null}