Newb fix for #bot healrotation

[kilst87]

I've spent a bit of time looking over the healrotation code (admittedly, I don't actually know C++ at all), and I think I've come up with a fix (or at least a partial one).

Replace (bot.cpp):
(in the function Bot::AddHealRotationMember())

for(int i = 0; i < 3; i++){

at line 12903

with:

int count = 0;
for (int i = 0; i < MaxHealRotationTargets; i++)
{
    if (_healRotationTargets[i] != 0)
    count++;
}
for(int i = 0; i < count; i++){

The tank/s weren't being set properly after calling AddHealRotationMember(). I'm assuming it's due to trying to set tanks that aren't actually there since the newly added healers would get stuck in the function Bot::AddHealRotationTarget().

I haven't thoroughly tested it, but with 1 tank and 3 healers, I was able to get a chain going, add a new healer, and stop the chain perfectly fine.