Added tls for http clients (#5766)

* Added global http client

* Added Do func for global http client

* Changed the code to use the global http client

* Fix http client in volume uploader

* Fixed pkg name

* Fixed http util funcs

* Fixed http client for bench_filer_upload

* Fixed http client for stress_filer_upload

* Fixed http client for filer_server_handlers_proxy

* Fixed http client for command_fs_merge_volumes

* Fixed http client for command_fs_merge_volumes and command_volume_fsck

* Fixed http client for s3api_server

* Added init global client for main funcs

* Rename global_client to client

* Changed:
- fixed NewHttpClient;
- added CheckIsHttpsClientEnabled func
- updated security.toml in scaffold

* Reduce the visibility of some functions in the util/http/client pkg

* Added the loadSecurityConfig function

* Use util.LoadSecurityConfiguration() in NewHttpClient func

weed/server/webdav_server.go

@@ -392,8 +392,13 @@ func (fs *WebDavFileSystem) Stat(ctx context.Context, name string) (os.FileInfo,
 }
 
 func (f *WebDavFile) saveDataAsChunk(reader io.Reader, name string, offset int64, tsNs int64) (chunk *filer_pb.FileChunk, err error) {
+	uploader, uploaderErr := operation.NewUploader()
+	if uploaderErr != nil {
+		glog.V(0).Infof("upload data %v: %v", f.name, uploaderErr)
+		return nil, fmt.Errorf("upload data: %v", uploaderErr)
+	}
 
-	fileId, uploadResult, flushErr, _ := operation.UploadWithRetry(
+	fileId, uploadResult, flushErr, _ := uploader.UploadWithRetry(
 		f.fs,
 		&filer_pb.AssignVolumeRequest{
 			Count:       1,