src/telegram: Add request options in getFileStream (#771)

Here it's request unable to use proxy options

src/telegram.js

@@ -1551,7 +1551,7 @@ class TelegramBot extends EventEmitter {
         fileStream.emit('info', {
           uri: fileURI,
         });
-        pump(streamedRequest({ uri: fileURI }), fileStream);
+        pump(streamedRequest(Object.assign({ uri: fileURI }, this.options.request)), fileStream);
       })
       .catch((error) => {
         fileStream.emit('error', error);