Fix for "attempt to index field 'ItemBindString' (a nil value)"

diff --git a/ElvUI_SLE/modules/characterframe/core.lua b/ElvUI_SLE/modules/characterframe/core.lua
index 7719c5e..34ae271 100644
--- a/ElvUI_SLE/modules/characterframe/core.lua
+++ b/ElvUI_SLE/modules/characterframe/core.lua
@@ -42,6 +42,13 @@ SLArmoryConstants = {
 		['504'] = 12, ['505'] = 16,
 	},

+	['ItemBindString'] = { -- Usually transmogrify string is located upper than bind string so we need to check this string for adding a transmogrify string in tooltip.
+			[ITEM_BIND_ON_EQUIP] = true,
+			[ITEM_BIND_ON_PICKUP] = true,
+			[ITEM_BIND_TO_ACCOUNT] = true,
+			[ITEM_BIND_TO_BNETACCOUNT] = true
+		},
+
 	['CanTransmogrifySlot'] = {
 			['HeadSlot'] = true,
 			['ShoulderSlot'] = true,