check auth only when enabled

weed/s3api/s3api_bucket_handlers.go

@@ -111,9 +111,11 @@ func (s3a *S3ApiServer) PutBucketHandler(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	if _, errCode = s3a.iam.authRequest(r, s3_constants.ACTION_ADMIN); errCode != s3err.ErrNone {
-		s3err.WriteErrorResponse(w, r, errCode)
-		return
+	if s3a.iam.isEnabled() {
+		if _, errCode = s3a.iam.authRequest(r, s3_constants.ACTION_ADMIN); errCode != s3err.ErrNone {
+			s3err.WriteErrorResponse(w, r, errCode)
+			return
+		}
 	}
 
 	fn := func(entry *filer_pb.Entry) {