I can't set a weapon buyable by a Detective

Hello.
[Excuse me for any grammatical errors]

I’ve downloaded this addon: [TTT/Sandbox] Dragon Elites

If I extract it using Gmad Extractor, and I go to:
gamemode/terrortown/entities/weapon/weapon_ttt_dragon_elites/shared.lua
and I edit the string:
(SWEP.CanBuy = { ROLE_TRAITOR }) in (SWEP.CanBuy = { ROLE_DETECTIVE })
and I put it into my server “gamemode/terrortown…”, anything change.

I use the collection system, for add an addons into my server, so this addons there is in my collection (for the materials, etc), and the file edited into my server.

Someone can help me?

Someone?

Can wee see the code to the entire file? Place the code between [lua][/lua] tags.