tests: make test-archive.t pass on py3.9 (issue6504)
Something got stricter at parsing URL query parameters and now the
parameters need to be separated by "&"; ";" is no longer allowed. See
issue6504 for details.
Differential Revision: https://phab.mercurial-scm.org/D10472
#require docutils gettext
$ $TESTDIR/check-gendoc it
checking for parse errors