Update KOSyncClient

reader.lua

@@ -96,6 +96,11 @@ local lfs = require("libs/libkoreader-lfs")
 local UIManager = require("ui/uimanager")
 local Device = require("device")
 local Font = require("ui/font")
+local random = require("random")
+
+if not G_reader_settings:readSetting("device_id") then
+    G_reader_settings:saveSetting("device_id", random.uuid())
+end
 
 -- read some global reader setting here:
 -- font