Fix for the LibItemSearch error.

diff --git a/libs/LibItemSearchGrid-1.0/LibItemSearchGrid-1.0.lua b/libs/LibItemSearchGrid-1.0/LibItemSearchGrid-1.0.lua
index 9580c24..132366b 100644
--- a/libs/LibItemSearchGrid-1.0/LibItemSearchGrid-1.0.lua
+++ b/libs/LibItemSearchGrid-1.0/LibItemSearchGrid-1.0.lua
@@ -457,7 +457,7 @@ end
 if IsAddOnLoaded('ItemRack') then
 	function ES_FindSets(setList, search, exactMatch)
 		for setName, _ in pairs(ItemRackUser.Sets) do
-			if ES_TrySetName(setName, search, exactMatch) then
+			if setName and ES_TrySetName(setName, search, exactMatch) then
 				if (search ~= '*') or (search == '*' and setName:sub(1,1) ~= '~') then --note: this additional tilde check skips internal ItemRack sets when doing a global set search (internal sets are prefixed with tilde, such as ~Unequip, and they contain temporary data that should not be part of a global search)
 					table.insert(setList, setName)
 				end
@@ -518,9 +518,9 @@ elseif IsAddOnLoaded('Wardrobe') then
 --Last Resort: Blizzard Equipment Manager
 else
 	function ES_FindSets(setList, search, exactMatch)
-		for i = 1, GetNumEquipmentSets() do
-			local setName = GetEquipmentSetInfo(i)
-			if ES_TrySetName(setName, search, exactMatch) then
+		for i = 1, C_EquipmentSet.GetNumEquipmentSets() do
+			local setName = C_EquipmentSet.GetEquipmentSetInfo(i)
+			if setName and ES_TrySetName(setName, search, exactMatch) then
 				table.insert(setList, setName)
 			end
 		end