How do I change this script so that the clock doesn't reset after one player dies?

Put this in a Script inside Workspace.

local players = {} -- table for players

local time = 2500
for i = 1,2500 do
    wait(1)
    time = time - 1
end

game.Players.PlayerAdded:connect(function(p) -- when a player is added
    local gui = p.PlayerGui:WaitForChild("GuiName") -- finds the gui
    if gui then
        local text = gui.TextLabel -- finds the TextLabel
        if text then
            p.CharacterAdded:connect(function(char) -- when their character is added
                local human = char:WaitForChild("Humanoid") -- finds the humanoid
                human.Died:connect(function() -- when a player dies
                    text.Text = "Game Over" -- changes text
                end)
            end)
            players:insert(p) -- puts the player in the table
        end
    end
end)

game.Players.PlayerRemoving:connect(function(p)
    table.remove(players,p) -- removes player from table, to avoid nil values
end

while true do -- repeats forever, can only have one infinite While loop in a script, only put these at the bottom of a script
    for _,v in pairs (players) do -- does this for every player
        local find = v.PlayerGui:FindFirstChild("GuiName")
        if find then
            local text = find.TextLabel
            if text then
                text.Text = tostring(time) -- changes text to time
            end
        end
    end
    wait()
end