Remove joined group notification from sitewide activity

Remove joined group notification from sitewide activity.php

<?php

add_action('bp_has_activities','my_denied_activity_new_member', 999, 2 );
function my_denied_activity_new_member( $a, $activities ){
	foreach( $activities->activities as $key => $activity ){
		if ( $activity->type =='joined_group') {
			unset( $activities->activities[$key] ); 
			$activities->activity_count = $activities->activity_count-1;
			$activities->total_activity_count = $activities->total_activity_count-1;
			$activities->pag_num = $activities->pag_num -1;
		}
	}
	$activities_new = array_values( $activities->activities );
	$activities->activities = $activities_new;
	return $activities;
}