uploader: link to `/policy/terms/`, not `terms.html` (#2864)
uploader: link to `/policy/terms/`, not `terms.html` (#2864)

Summary:
We’ll have a redirect in place, but we’d prefer that this be the
canonical path.

wchargin-branch: uploader-terms-slash
tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard