nginx_vhost: add check whether vhost required
nginx_vhost: add check whether vhost required

djtfmartin/ala-install,sadeghim/ala-install,AtlasOfLivingAustralia/ala-install,AtlasOfLivingAustralia/ala-install,djtfmartin/ala-install,sadeghim/ala-install,sadeghim/ala-install,AtlasOfLivingAustralia/ala-install,sadeghim/ala-install,djtfmartin/ala-install,AtlasOfLivingAustralia/ala-install,AtlasOfLivingAustralia/ala-install,djtfmartin/ala-install