[3.11] community/phpmyadmin: upgrade to 4.9.4
Backport of !2923 (merged) because of security fix https://www.phpmyadmin.net/news/2020/1/8/phpmyadmin-494-and-501-are-released/
Backport of !2923 (merged) because of security fix https://www.phpmyadmin.net/news/2020/1/8/phpmyadmin-494-and-501-are-released/