Fix crash from sum on flag

Fixes #9263

Author: LocalIdentity

src/Modules/CalcOffence.lua

@@ -1048,7 +1048,8 @@ function calcs.offence(env, actor, activeSkill)
 		else
 			output.SplitCount = skillModList:Sum("BASE", skillCfg, "SplitCount") + enemyDB:Sum("BASE", skillCfg, "SelfSplitCount")
 			if skillModList:Flag(skillCfg, "AdditionalProjectilesAddSplitsInstead") then
-				output.SplitCount = output.SplitCount + skillModList:Flag(skillCfg, "SingleProjectile") and 0 or m_floor((skillModList:Sum("BASE", skillCfg, "ProjectileCount") - 1) * skillModList:More(skillCfg, "ProjectileCount"))
+				local addedSplits = skillModList:Flag(skillCfg, "SingleProjectile") and 0 or m_floor((skillModList:Sum("BASE", skillCfg, "ProjectileCount") - 1) * skillModList:More(skillCfg, "ProjectileCount"))
+				output.SplitCount = output.SplitCount + addedSplits
 			end
 			if skillModList:Flag(skillCfg, "AdditionalChainsAddSplitsInstead") then
 				output.SplitCount = output.SplitCount + skillModList:Sum("BASE", skillCfg, "ChainCountMax")