dietpi-patches: harden group removal

Remove www-data user from pihole group as well, if it is not the first member.

.update/patches

@@ -2132,7 +2132,7 @@ Patch_9_11()
 			[[ -d '/etc/nginx/sites-dietpi' ]] && G_EXEC rm -f /etc/nginx/sites-dietpi/dietpi-pihole*
 
 			# Remove www-data user from pihole group
-			getent group pihole | grep -Eq ':www-data(,|$)' && G_EXEC gpasswd -d www-data pihole
+			getent group pihole | grep -Eq '(:|,)www-data(,|$)' && G_EXEC gpasswd -d www-data pihole
 
 			# Change web UI port to 8089 to avoid conflict with webservers and other web applications
 			G_EXEC pihole-FTL --config webserver.port 8089