Fix CONFIG REWRITE handling of unknown options.
Fix CONFIG REWRITE handling of unknown options.

There were two problems with the implementation.

1) "save" was not correctly processed when no save point was configured,
   as reported in issue #1416.
2) The way the code checked if an option existed in the "processed"
   dictionary was wrong, as we add the element with as a key associated
   with a NULL value, so dictFetchValue() can't be used to check for
   existance, but dictFind() must be used, that returns NULL only if the
   entry does not exist at all.

janeasystems/redis,jacklee0810/redis,crask/redis-cutter,StartTheShift/redis-shift,laurencee/redis,nandhanurrevanth/redis,ideaar/redis,quangnguyen90/redis,sidsen/redis,janeasystems/redis,enginekit/redis,shanegxxiao/redis,erwin00776/redis-2.8-optimize,jqk6/redis,adamweixuan/redis,shanegxxiao/redis,laurencee/redis,ScottKaiGu/redis,kts12345/redis,kts12345/redis,adamweixuan/redis,ideaar/redis,shanegxxiao/redis,powerumc/MyRedis_old,damy/redis,adamweixuan/redis,liqiang199105/redis,miminus/redis,kts12345/redis,jacklee0810/redis,kolonse/redis,ScottKaiGu/redis,Cybermaxs/redis,miminus/redis,oaastest/redis,adamweixuan/redis,janeasystems/redis,upsoft/redis,alpha8/redis,jaambee/redis,shanegxxiao/redis,Cybermaxs/redis,laurencee/redis,adamweixuan/redis,damy/redis,upsoft/redis,liqiang199105/redis,Jonavin/redis,erwin00776/redis-2.8-optimize,sidsen/redis,quangnguyen90/redis,miminus/redis,janeasystems/redis,oaastest/redis,alpha8/redis,liqiang199105/redis,fanxu/redis,enginekit/redis,kolonse/redis,ScottKaiGu/redis,crask/redis-cutter,jacklee0810/redis,nandhanurrevanth/redis,quangnguyen90/redis,janeasystems/redis,powerumc/MyRedis_old,powerumc/MyRedis,fanxu/redis,jqk6/redis,crask/redis-cutter,miminus/redis,ScottKaiGu/redis,sidsen/redis,jqk6/redis,LittlePeng/redis,jaambee/redis,jacklee0810/redis,ideaar/redis,alpha8/redis,upsoft/redis,jacklee0810/redis,sidsen/redis,sidsen/redis,fanxu/redis,StartTheShift/redis-shift,damy/redis,kolonse/redis,Jonavin/redis,LittlePeng/redis,fanxu/redis,jqk6/redis,liqiang199105/redis,alpha8/redis,laurencee/redis,ideaar/redis,ScottKaiGu/redis,Jonavin/redis,enginekit/redis,quangnguyen90/redis,ideaar/redis,nandhanurrevanth/redis,hanmichael/redis,powerumc/MyRedis,hanmichael/redis,powerumc/MyRedis_old,jaambee/redis,erwin00776/redis-2.8-optimize,shanegxxiao/redis,laurencee/redis,erwin00776/redis-2.8-optimize,jaambee/redis,kolonse/redis,Cybermaxs/redis,powerumc/MyRedis_old,LittlePeng/redis,upsoft/redis,sidsen/redis,quangnguyen90/redis,Cybermaxs/redis,kts12345/redis,oaastest/redis,damy/redis,oaastest/redis,nandhanurrevanth/redis,nandhanurrevanth/redis,kolonse/redis,alpha8/redis,upsoft/redis,liqiang199105/redis,kts12345/redis,Jonavin/redis,enginekit/redis,powerumc/MyRedis,Jonavin/redis,oaastest/redis,StartTheShift/redis-shift,jqk6/redis,hanmichael/redis,miminus/redis,hanmichael/redis,hanmichael/redis,damy/redis,jaambee/redis,enginekit/redis,Cybermaxs/redis