Used math.abs instead of abs

diff --git a/WeightsWatcher.lua b/WeightsWatcher.lua
index 58c57f4..663fa71 100644
--- a/WeightsWatcher.lua
+++ b/WeightsWatcher.lua
@@ -983,7 +983,7 @@ function WeightsWatcher.calculateWeight(bareItemStats, itemStats, weightsScale)

 		for _, value in pairs(weightsScale) do
 			if type(value) == "number" then
-				total = total + abs(value)
+				total = total + math.abs(value)
 			end
 		end
 		if total == 0 then