Update transformer_tutorial.rst

Update changes to deprecation .rst file as seen in #2922

Author: loganthomas

beginner_source/transformer_tutorial.rst

@@ -4,4 +4,5 @@ Language Modeling with ``nn.Transformer`` and torchtext
 The content is deprecated.
 
 .. raw:: html
-   <meta http-equiv="refresh" content="0; url=https://pytorch.org/tutorials/">
+
+   <meta http-equiv="Refresh" content="0; url='https://pytorch.org/tutorials/'" />