Remove GameEndAlly?

[rute]

GameEndAlly = "This NPC will cause the game to end if killed." Used in default HL2 maps. (vital ally).

I want game to not end if I kill something that is vital ally.

I've done this:
[lua]
local function Allyno()
for k,v in pairs(ents.FindByClass("npc_alyx")) do
v:SetKeyValue("GameEndAlly","0")
end
timer.Simple(1,Allyno)
end
Allyno()
[/lua]

However game still likes to end when I kill Alyx. What to do?