simplemerge: delete unused find_unconflicted()
The function has been unused ever since it was introduced in
465b9ea02868 (Import 3-way merge code from bzr, 2007-04-16).
Differential Revision: https://phab.mercurial-scm.org/D9832
#require serve
$ hg clone http://localhost:$HGPORT/ copy
abort: * (glob)
[100]
$ 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)
[100]
$ killdaemons.py