Handle nil case of empty decompression

lib/packet.rb

@@ -30,7 +30,11 @@ class Packet
     return unless flags_compressed
 
     @payload = @huffman.decompress(@payload.unpack('C*'))
-    @payload = @payload.pack('C*')
+    if @payload.nil?
+      @payload = ''
+    else
+      @payload = @payload.pack('C*')
+    end
   end
 
   def annotate_first_row(bytes)