Removed a usage of Mob::DistNoRootNoZ and used ComparativeDistanceNoZ instead

zone/merc.cpp

@@ -1318,7 +1318,7 @@ bool Merc::IsMercCasterCombatRange(Mob *target) {
 		// half the max so the merc doesn't always stop at max range to allow combat movement
 		range *= .5;
 
-		float targetDistance = DistNoRootNoZ(*target);
+		float targetDistance = ComparativeDistanceNoZ(m_Position, target->GetPosition());
 
 		if(targetDistance > range)
 			result = false;