shelve: actually test corrupted shelve state
The test was previous moving the corrupted shelve state file as an histedit
state file.
Differential Revision: https://phab.mercurial-scm.org/D3690
#require serve
$ 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