Add Featured Image to Events Calendar Month View

single-event.php

<?php
/**
 * Month Single Event
 * This file contains one event in the month view
 *
 * Override this template in your own theme by creating a file at [your-theme]/tribe-events/month/single-event.php
 *
 * @package TribeEventsCalendar
 *
 */

if ( ! defined( 'ABSPATH' ) ) {
	die( '-1' );
} ?>

<?php
global $post;
$day      = tribe_events_get_current_month_day();
$event_id = "{$post->ID}-{$day['daynum']}";
$start    = tribe_get_start_date( $post, false, 'U' );
$end      = tribe_get_end_date( $post, false, 'U' );

?>

<div id="tribe-events-event-<?php echo $event_id ?>" class="<?php tribe_events_event_classes() ?>" data-tribejson='<?php echo tribe_events_template_data( $post ); ?>'>
	<h3 class="tribe-events-month-event-title entry-title summary"><a href="<?php tribe_event_link( $post ); ?>" class="url"><?php the_title() ?></a></h3>
	<?php if (has_post_thumbnail() && 1 === $day['total_events']) : ?>
		<div class="tribe-events-event-thumb"><?php echo the_post_thumbnail(array(90,90));?></div>
	<?php endif; ?>
</div><!-- #tribe-events-event-# -->