点击进入游戏按钮的时候报错，

问题描述细：
只是单纯点击进入游戏按钮。没有其他操作

报错堆栈
```
Traceback (most recent call last):
File "airtest\cli\runner.py", line 62, in runTest
File "F:\code\airtest\test2.air\test2.py", line 10, in
poco("imgStart").click()
File "poco\proxy.py", line 23, in wrapped
File "poco\proxy.py", line 283, in click
File "poco\proxy.py", line 563, in get_position
File "poco\proxy.py", line 39, in wrapped
File "poco\proxy.py", line 684, in attr
File "poco\proxy.py", line 819, in _do_query
File "poco\freezeui\hierarchy.py", line 89, in select
File "poco\sdk\Selector.py", line 77, in select
File "poco\sdk\Selector.py", line 70, in getRoot
File "poco\freezeui\hierarchy.py", line 35, in getRoot
File "poco\utils\simplerpc\utils.py", line 13, in new_func
File "poco\utils\simplerpc\simplerpc.py", line 78, in wait
poco.utils.simplerpc.simplerpc.RpcTimeoutError: (rid=2a74730d-c0f1-433a-89a7-ef34c5eefb27)
```
设备：
mumu模拟器

Reproduce the failure on the reported MuMu emulator using the test2.air/test2.py step that calls poco("imgStart").click(). Start with poco/proxy.py and follow the timeout through poco/freezeui/hierarchy.py, poco/sdk/Selector.py, and poco/utils/simplerpc/simplerpc.py. Done means the game-entry click completes without RpcTimeoutError, with a focused regression test if the project provides one.

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