Tweak to bloated zombie.

Given that this variant is bloated with putrid gas, I think having it move faster than the normal variant is a bit weird, hence the nerf to speed (For reference, normal zombies have 70 speed, boomer 55)
The buff to hp is to compensate to the speed nerf, and to make it less vulnerable to 2, 3 rock thow.

I also changed the special suicide attack to trigger when it either 1 title away or adjacent from player. The reason is that the gas cloud is a 5 x 5 area and continue to expand afterward, a less strict trigger will give more chance to get that gas in the character's face.
May revisit this later but for now we'll see how it works.  Speed 60 ought to let folks escape.