A couple of GNB changes

[baklava151]

I don't know how likely it would be if they did this in 7.0 but I wish they'd revert the number of max cartridges GNB can hold back down to 2 and make DD cost only 1, along with whatever potency adjustments that needs. Needing three cartridges going into your one-minute gives you very little leeway on missing GCDs, which to be fair it's pretty hard to lose uptime in EW but it still happens on occasion.