test: use bundle2 in test-http-proxy
The proxy test does not care about what protocol is used, but the new
protocol implies different traffic (and therefore different log
output). We switch it to bundle2 early to minimise the noise of using
bundle2 for exchange by default.
$ hg init
$ touch unknown
$ touch a
$ hg add a
$ hg ci -m "1"
$ touch b
$ hg add b
$ hg ci -m "2"
Should show unknown
$ hg status
? unknown
$ hg revert -r 0 --all
removing b
Should show unknown and b removed
$ hg status
R b
? unknown
Should show a and unknown
$ ls
a
unknown