Take into account the possibility of custom bulk buy amounts

[quazillionaire]

Bug description

Changing Game.buyBulk to a non-standard value causes the game to crash here:

CookieMonster/src/Disp/InfoBars/BottomBar.js

Line 85 in 69b923d

target[i].bonus,

I don't know about handling custom bulk buy amounts, but presumably it should be fairly simple to avoid the crash, at least.

To reproduce

Type Game.buyBulk = 2 into the dev console.

Browser / Steam / Version

Steam, v. 2.053