py3: use list() to get a list of items using dict.items()
dict.items() on Python 3 returns a generator over the values of the dictionary,
hence we can't delete elements while iterating over dict.items() in Python 3.
Differential Revision: https://phab.mercurial-scm.org/D1799
#require serve killdaemons
$ hg clone http://localhost:$HGPORT/ copy
abort: * (glob)
[255]
$ test -d copy
[1]
$ $PYTHON "$TESTDIR/dumbhttp.py" -p $HGPORT --pid dumb.pid
$ cat dumb.pid >> $DAEMON_PIDS
$ hg clone http://localhost:$HGPORT/foo copy2
abort: HTTP Error 404: * (glob)
[255]
$ killdaemons.py