fix some TODOs

proxy/pkg/cs3/client.go

@@ -5,12 +5,13 @@ import (
 	proxytracing "github.com/owncloud/ocis/proxy/pkg/tracing"
 	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 )
 
 func newConn(endpoint string) (*grpc.ClientConn, error) {
 	conn, err := grpc.Dial(
 		endpoint,
-		grpc.WithInsecure(), //TODO: depreciated
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
 		grpc.WithUnaryInterceptor(
 			otelgrpc.UnaryClientInterceptor(
 				otelgrpc.WithTracerProvider(