Fix the nil error received when opening the options pane

diff --git a/ARLFrame.lua b/ARLFrame.lua
index a096e26..ce54e3d 100644
--- a/ARLFrame.lua
+++ b/ARLFrame.lua
@@ -1230,7 +1230,7 @@ function addon.numFilters()

 	-- IMPORTANT: If the number of filters we're maintaining changes, you'll need to change the FilterValueMap
 	-- at the end (of CreateFrame), as well as the following index value:
-	local MaxFilters = 87
+	local MaxFilters = 86

 	local total = 0
 	local active = 0