refactor(server): explicitly check inventory data is a table

Some people are triggering setPlayerInventory with the wrong values.
(or rather some ESX change broke their inventory data)

server.lua

@@ -29,7 +29,7 @@ function server.setPlayerInventory(player, data)
  local inventory = {}
  local totalWeight = 0
 
- if data and next(data) then
+ if type(data) == 'table' then
  local ostime = os.time()
 
  for _, v in pairs(data) do