Slight optimization to //set

Just noticed I box the one type version in a list, to avoid testing
whether it's the one type version, but have to test for that to decide
whether to box it or not. Should shave like a whole 3ms from each //set
command.

worldedit/manipulations.lua

@@ -25,8 +25,11 @@ end
 
 --sets a region defined by positions `pos1` and `pos2` to `nodename`, returning the number of nodes filled
 worldedit.set = function(pos1, pos2, nodenames)
+    local oneNode
     if type(nodenames) == 'string' then
-        nodenames = {nodenames}
+        oneNode = true
+    else
+        oneNode = false
     end
 
 	local pos1, pos2 = worldedit.sort_pos(pos1, pos2)
@@ -48,10 +51,10 @@ worldedit.set = function(pos1, pos2, nodenames)
     for i,v in ipairs(nodenames) do
         node_ids[i] = minetest.get_content_id(nodenames[i])
     end
-	if #node_ids == 1 then --only one type of node
-		local id = node_ids[1]
+	if oneNode then --only one type of node
+		local id = node_ids
 		for i in area:iterp(pos1, pos2) do nodes[i] = id end --fill area with node
-	else --several tpyes of nodes specified
+	else --several types of nodes specified
 		local id_count, rand = #node_ids, math.random
 		for i in area:iterp(pos1, pos2) do nodes[i] = node_ids[rand(id_count)] end --fill randomly with all types of specified nodes
 	end