manifest: now that there's only one legacy.py, exclude it
After the last patch, this file is only included because of package_dir in
setup.py (i.e. just once), so we can ignore it with just one clause. But
package_dir starts with "./", so we need to add it to the pattern.
test-drop.t
test-inhibit.t
test-simple4server.t
tests/test-simple4server-bundle2.t