Revert "fix for libtotem.lua crashing with Invalid spell slot"

This reverts commit cc61fbf6d7.

libs/libspell.lua

@@ -108,9 +108,6 @@ function libspell.GetSpellInfo(index, bookType)
       name = GetSpellName(id, bookType)
     end
   else
-    if not bookType or (bookType ~= BOOKTYPE_SPELL and bookType ~= BOOKTYPE_PET) then
-      return nil
-    end
     name, rank = GetSpellName(index, bookType)
     id, bookType = libspell.GetSpellIndex(name, rank)
   end

libs/libtotem.lua

@@ -252,8 +252,6 @@ end)
 
 -- Hook CastSpell to store pending name/icon per slot
 hooksecurefunc("CastSpell", function(id, bookType)
-  if not id or not bookType then return end
-  if bookType ~= BOOKTYPE_SPELL and bookType ~= BOOKTYPE_PET then return end
   local name, rank, icon, _, _, _, spellId = libspell.GetSpellInfo(id, bookType)
   if not name then return end
   libtotem:CheckAddQueue(name, rank, icon, spellId)