hgweb: ensure Content-Length and Content-Type are not promoted to HTTP_ on py3 In stabilizing test-lfs-serve-access.t for py3, the server started asserting on blob upload: Environment should not have the key: HTTP_CONTENT_LENGTH (use CONTENT_LENGTH instead) It could be avoided by explicitly setting the Content-Length header on the client side. I didn't go back to py2, but printing the original header here in py37 revealed 'Content-length' when sent to the error log.