Fix: Handle regression caused by gorilla mux v1.7.0 (minio#7625)

PR minio#7595 fixed part of the regression, but did not handle the
scenario, where in docker, the internal port is different from
the port on the host.

This PR modifies the regular expression such that all the
scenarios are handled.

Fixes minio#7619

cmd/api-router.go

@@ -17,7 +17,6 @@
 package cmd
 
 import (
-	"net"
 	"net/http"
 
 	"github.com/gorilla/mux"
@@ -46,13 +45,8 @@ func registerAPIRouter(router *mux.Router, encryptionEnabled bool) {
 	apiRouter := router.PathPrefix("/").Subrouter()
 	var routers []*mux.Router
 	for _, domainName := range globalDomainNames {
-		var hostPort string
-		if globalMinioPort != "443" && globalMinioPort != "80" {
-			hostPort = net.JoinHostPort(domainName, globalMinioPort)
-		} else {
-			hostPort = domainName
-		}
-		routers = append(routers, apiRouter.Host("{bucket:.+}."+hostPort).Subrouter())
+		routers = append(routers, apiRouter.Host("{bucket:.+}."+domainName).Subrouter())
+		routers = append(routers, apiRouter.Host("{bucket:.+}."+domainName+":{port:.*}").Subrouter())
 	}
 	routers = append(routers, apiRouter.PathPrefix("/{bucket}").Subrouter())