Update icon border in the merchantframe to use quality color.

diff --git a/ElvUI_SLE/skins/blizzard/merchant.lua b/ElvUI_SLE/skins/blizzard/merchant.lua
index 255eb0a..8941c96 100644
--- a/ElvUI_SLE/skins/blizzard/merchant.lua
+++ b/ElvUI_SLE/skins/blizzard/merchant.lua
@@ -38,6 +38,13 @@ local function SkinVendorItems(i)
 	icon:SetTexCoord(unpack(E.TexCoords))
 	icon:SetInside()
 	iconBorder:SetAlpha(0)
+	hooksecurefunc(iconBorder, 'SetVertexColor', function(self, r, g, b)
+		self:GetParent():SetBackdropBorderColor(r, g, b)
+		self:SetTexture("")
+	end)
+	hooksecurefunc(iconBorder, 'Hide', function(self)
+ 		self:GetParent():SetBackdropBorderColor(unpack(E.media.bordercolor))
+ 	end)

 	_G["MerchantItem"..i.."MoneyFrame"]:ClearAllPoints()
 	_G["MerchantItem"..i.."MoneyFrame"]:Point("BOTTOMLEFT", button, "BOTTOMRIGHT", 3, 0)