Update TensorPipe submodule (#37729)

Summary:
In order to include these fixes that were blocking #35483:
- pytorch/tensorpipe@673eda9
- pytorch/tensorpipe@ff8d173
- pytorch/tensorpipe@c733678

Pull Request resolved: #37729

Reviewed By: beauby

Differential Revision: D21378972

Pulled By: lw

fbshipit-source-id: 3375fe1fa6e79817da3bb033127c3c8f31c3ffc3

.gitmodules

@@ -129,4 +129,4 @@
 [submodule "third_party/tensorpipe"]
     ignore = dirty
     path = third_party/tensorpipe
-    url = https://github.com/pytorch/tensorpipe
+    url = https://github.com/pytorch/tensorpipe.git