PLT-5118 moving to last_picture_update for the profile img (#4985)

webapp/components/user_list_row.jsx

@@ -64,7 +64,7 @@ export default function UserListRow({user, extraInfo, actions, actionProps, acti
             className='more-modal__row'
         >
             <ProfilePicture
-                src={`${Client.getUsersRoute()}/${user.id}/image?time=${user.update_at}`}
+                src={`${Client.getUsersRoute()}/${user.id}/image?time=${user.last_picture_update}`}
                 status={status}
                 width='32'
                 height='32'