apdu.lua: convert to integer #atr output

Lua 5.3 changes the way behaves with floats and integers.
To maintain the same output as with Lua 5.2 convert #atr to integer.
This way cold ATR appears as for example 23 instead 23.0.

Signed-off-by: David Santamaría Rogado <[email protected]>

Author: howl

dot_cardpeek_dir/scripts/lib/apdu.lua

@@ -113,7 +113,7 @@ function card.tree_startup(title)
 
 	atrnode = mycard:append({ classname="atr",
 			          label="cold ATR",
-			  	  size=#atr,
+			  	  size=math.tointeger(#atr),
 				  val=atr })
 
 	if candidates then