Remove NaN values (#667)

NaN can cause problems (and errors) if the receiving node doesn't check for it, this PR makes it so NaN values are removed from digiline messages.

mesecons_luacontroller/init.lua

@@ -388,7 +388,10 @@ local function clean_and_weigh_digiline_message(msg, back_references)
 		return msg, #msg + 25
 	elseif t == "number" then
 		-- Numbers are passed by value so need not be touched, and cost 8 bytes
-		-- as all numbers in Lua are doubles.
+		-- as all numbers in Lua are doubles. NaN values are removed.
+		if msg ~= msg then
+			return nil, 0
+		end
 		return msg, 8
 	elseif t == "boolean" then
 		-- Booleans are passed by value so need not be touched, and cost 1