Improve the https scheme matching (#508)

Improve the https scheme matching

---------

Co-authored-by: Erik Pellizzon <[email protected]>

https.go

@@ -11,7 +11,6 @@ import (
 	"net/http"
 	"net/url"
 	"os"
-	"regexp"
 	"strconv"
 	"strings"
 	"sync"
@@ -34,7 +33,6 @@ var (
 	MitmConnect     = &ConnectAction{Action: ConnectMitm, TLSConfig: TLSConfigFromCA(&GoproxyCa)}
 	HTTPMitmConnect = &ConnectAction{Action: ConnectHTTPMitm, TLSConfig: TLSConfigFromCA(&GoproxyCa)}
 	RejectConnect   = &ConnectAction{Action: ConnectReject, TLSConfig: TLSConfigFromCA(&GoproxyCa)}
-	httpsRegexp     = regexp.MustCompile(`^https:\/\/`)
 )
 
 // ConnectAction enables the caller to override the standard connect flow.
@@ -232,7 +230,7 @@ func (proxy *ProxyHttpServer) handleHttps(w http.ResponseWriter, r *http.Request
 				req.RemoteAddr = r.RemoteAddr // since we're converting the request, need to carry over the original connecting IP as well
 				ctx.Logf("req %v", r.Host)
 
-				if !httpsRegexp.MatchString(req.URL.String()) {
+				if !strings.HasPrefix(req.URL.String(), "https://") {
 					req.URL, err = url.Parse("https://" + r.Host + req.URL.String())
 				}