remove another debug line

diff --git a/core.lua b/core.lua
index 3c2ddc5..f7672e0 100644
--- a/core.lua
+++ b/core.lua
@@ -1700,7 +1700,6 @@ do

 					-- If we have it in the mapping, set the lower rank spell to known
 					if overwritemap[SpellID] then
-						self:Print("Marking " .. overwritemap[SpellID])
 						local overwriterecipe = recipe_list[overwritemap[SpellID]]
 						if overwriterecipe then
 							togglerecipe(overwriterecipe, is_linked)