Use environment DialContext and Listen everywhere

internal/component/triplestore/database.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"io"
 	"mime/multipart"
-	"net"
 	"net/http"
 
 	"github.com/FAU-CDI/wisski-distillery/pkg/logging"
@@ -64,10 +63,8 @@ func (ts Triplestore) OpenRaw(method, url string, body interface{}, bodyName str
 	// create the request object
 	client := &http.Client{
 		Transport: &http.Transport{
-			Dial: ts.Environment.Dial,
-			DialTLS: func(network, addr string) (net.Conn, error) {
-				return nil, errors.New("not implemented")
-			},
+			DialContext:       ts.Environment.DialContext,
+			DisableKeepAlives: true,
 		},
 	}
 	req, err := http.NewRequest(method, ts.BaseURL+url, reader)