Support multiple VIRTUAL_PORT alongside VIRTUAL_HOST

See nginx-proxy/nginx-proxy#59

Final solution: VIRTUAL_HOST="example.com:8080,example.org:8081"

nginx.tmpl

@@ -102,6 +102,13 @@ upstream {{ $host }} {
 				{{ if eq $addrLen 1 }}
 					{{ $address := index $container.Addresses 0 }}
 					{{ template "upstream" (dict "Container" $container "Address" $address "Network" $containerNetwork) }}
+				{{/* If more than one port exposed, use the one matching after the colon in VIRTUAL_HOST env var */}}
+				{{ else if (and ($port ) (ne $port $host) ) }}
+					{{ range $address := $container.Addresses }}
+						{{ if eq $address.Port $port }}
+							{{ template "upstream" (dict "Container" $container "Address" $address "Network" $containerNetwork) }}
+						{{ end }}
+					{{ end }}
 				{{/* If more than one port exposed, use the one matching VIRTUAL_PORT env var, falling back to standard web port 80 */}}
 				{{ else }}
 					{{ $port := coalesce $container.Env.VIRTUAL_PORT "80" }}