Bump github.com/gorilla/mux from 1.7.4 to 1.8.1

Bumps [github.com/gorilla/mux](https://github.com/gorilla/mux) from 1.7.4 to 1.8.1.
- [Release notes](https://github.com/gorilla/mux/releases)
- [Commits](https://github.com/gorilla/mux/compare/v1.7.4...v1.8.1)

---
updated-dependencies:
- dependency-name: github.com/gorilla/mux
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

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

@@ -22,10 +22,10 @@ type routeRegexpOptions struct {
 type regexpType int
 
 const (
-	regexpTypePath   regexpType = 0
-	regexpTypeHost   regexpType = 1
-	regexpTypePrefix regexpType = 2
-	regexpTypeQuery  regexpType = 3
+	regexpTypePath regexpType = iota
+	regexpTypeHost
+	regexpTypePrefix
+	regexpTypeQuery
 )
 
 // newRouteRegexp parses a route template and returns a routeRegexp,
@@ -195,7 +195,7 @@ func (r *routeRegexp) Match(req *http.Request, match *RouteMatch) bool {
 
 // url builds a URL part using the given values.
 func (r *routeRegexp) url(values map[string]string) (string, error) {
-	urlValues := make([]interface{}, len(r.varsN), len(r.varsN))
+	urlValues := make([]interface{}, len(r.varsN))
 	for k, v := range r.varsN {
 		value, ok := values[v]
 		if !ok {
@@ -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)