wording fix for gravepact and renewal

The "have" word is usually coupled with a "+" signifier.
For example, the Sacrifice notable says "minions have +10"...
while gravepact and renewal are missing the "+", which I believe is intended.
Currently it reads as if they will only have 10% chance to deal double damage while on full life, but I believe they actually have 15 because both of these should have a "+" in the wording.