fix bug that caused rediagonalization of ring ownership on every node removal
fix bug that caused rediagonalization of ring ownership on every node removal

amyvmiwei/riak,xuejianhai/riak_search,biddyweb/riak,GabrielNicolasAvellaneda/riak,wwezhuimeng/riak_search,planobe/riak,yangchengjian/riak,authbox-lib/riak,elkingtonmcb/riak,planobe/riak,xuejianhai/riak,basho/riak_search,xuejianhai/riak_search,basho/riak,glickbot/riak,wwezhuimeng/riak_search,basho/riak_search,laurenrother/riak,DavidAlphaFox/riak