fix openthread version

Author: Wiktor Grajkowski

scripts/build/builders/qpg.py

@@ -118,7 +118,7 @@ def __init__(self,
         self.update_image = update_image
 
     def GnBuildArgs(self):
-        args = ['qpg_target_ic=\"%s\" qpg_flavour=\"%s\"' % (self.board.GnArgName(), self.flavour.GnFlavourName())]
+        args = ['qpg_target_ic=\"%s\" qpg_flavour=\"%s\", openthread_config_thread_version=\"%s\"' % (self.board.GnArgName(), self.flavour.GnFlavourName()), "1.3"]
         if self.enable_rpcs:
             args.append('import("//with_pw_rpc.gni")')
         if self.update_image: