tests/test-issue672

httprepo: use separate handlers for HTTP and HTTPS

This is needed to keep the code in keepalive.py from sharing
the same connection between HTTP and HTTPS.

52ce0d6bc375 explains why we were using a single handler.

This should fix issue892.

#!/bin/sh

# 0-2-4
#  \ \ \
#   1-3-5
#
# rename in #1, content change in #4.

hg init t
cd t

touch 1
touch 2
hg commit -Am init -d "0 0"  # 0

hg rename 1 1a
hg commit -m rename -d "0 0" # 1

hg co -C 0
echo unrelated >> 2
hg ci -m unrelated1 -d "0 0"  # 2

hg merge --debug 1
hg ci -m merge1 -d "0 0" # 3

hg co -C 2
echo hello >> 1
hg ci -m unrelated2 -d "0 0" # 4

hg co -C 3
hg merge -y --debug 4

hg co -C 4
hg merge -y --debug 3