bitbake: server/process: Simplfy idle callback handler function

Having the idle callbacks abstracted via the configuration object
makes no sense. Its like this for historical reasons from the
multiple server backends but we don't need this now so simplfy.

(Bitbake rev: e56c49717355c9493b07d5fc80981a95ad8a0ec8)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/command.py

@@ -84,7 +84,7 @@ class Command:
         if command not in CommandsAsync.__dict__:
             return None, "No such command"
         self.currentAsyncCommand = (command, commandline)
-        self.cooker.configuration.server_register_idlecallback(self.cooker.runCommands, self.cooker)
+        self.cooker.idleCallBackRegister(self.cooker.runCommands, self.cooker)
         return True, None
 
     def runAsyncCommand(self):