vendor: update buildkit to v0.8

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/gorilla/mux/mux.go

@@ -435,8 +435,7 @@ func Vars(r *http.Request) map[string]string {
 // CurrentRoute returns the matched route for the current request, if any.
 // This only works when called inside the handler of the matched route
 // because the matched route is stored in the request context which is cleared
-// after the handler returns, unless the KeepContext option is set on the
-// Router.
+// after the handler returns.
 func CurrentRoute(r *http.Request) *Route {
 	if rv := r.Context().Value(routeKey); rv != nil {
 		return rv.(*Route)

vendor/github.com/gorilla/mux/regexp.go

@@ -325,6 +325,12 @@ func (v routeRegexpGroup) setMatch(req *http.Request, m *RouteMatch, r *Route) {
 	// Store host variables.
 	if v.host != nil {
 		host := getHost(req)
+		if v.host.wildcardHostPort {
+			// Don't be strict on the port match
+			if i := strings.Index(host, ":"); i != -1 {
+				host = host[:i]
+			}
+		}
 		matches := v.host.regexp.FindStringSubmatchIndex(host)
 		if len(matches) > 0 {
 			extractVars(host, matches, v.host.varsN, m.Vars)