fix bug that not all records are returned when num_each_query has been s...

local servercount =mongoCollection:count({})
local cursor = mongoCollection:find({},{},0)
local count = 0	
for index, item in cursor:pairs() do
	count = count+1
end 
----out put
servercount = count+101  -- when total count is greater than 101
I found self.i didn't reset when self.resutls had been reassigned in cursor.lua file, so I add localIndex to solve it.