httppeer: close the temporary bundle file after two-way streaming it This fixes several push tests in test-bundle2-exchange.t that were failing on Windows with messages like the following: $ hg -R main push http://localhost:$HGPORT2/ -r 32af7686d403 \ --bookmark book_32af pushing to http://localhost:$HGPORT2/ searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 1 changes to 1 files remote: 1 new obsolescence markers updating bookmark book_32af abort: The process cannot access the file because it is being used by another process: 'C:\path\to\tmp\bundle.hg' [255]