:(

Go in the server menu then click on war and edit it and put server resource packs to disabled (http://prntscr.com/h94j7a) :u It doesn't have to auto download

 

In addition to what @sjuka_legogubbar said, you can set server resource packs to "prompt" (which, honestly, I'd recommend you always set if you don't disable it completely). Whenever you join the server, you can press Esc and you won't auto download the resource pack, but you can also choose to download the resource pack if you want.

Also, in your Minecraft directory, there's a folder called "server-resource-packs" (or similar) - go there and move any resource packs you want into your normal resource packs folder, and you can use the server's resource packs as if they were regular resource packs.

Question answered, and user request - locked. Another staff member locked this before, but didn't leave any message. Just leaving this here to avoid confusion.