被调用的云函数（已设置独立运行超时60秒）多少超时？有没有官方说法？这个能放开别限制吗？按云函数自身设置超时为准。目前实测51秒会超时，10来秒正常。超时返回如下错误：

{"errorCode":1,"errorMessage":"user code exception caught","stackTrace":"errCode: -1 unknown error | errMsg: callFunction:fail Error: ESOCKETTIMEDOUT; at callFunction api; \nError: errCode: -1 unknown error | errMsg: callFunction:fail Error: ESOCKETTIMEDOUT; at callFunction api; \n    at returnAsCloudSDKError (/var/user/node_modules/wx-server-sdk/index.js:7814:16)\n    at Object.returnAsFinalCloudSDKError (/var/user/node_modules/wx-server-sdk/index.js:7828:15)\n    at Promise (/var/user/node_modules/wx-server-sdk/index.js:1745:39)\n    at \u003canonymous\u003e\n    at process._tickCallback (internal/process/next_tick.js:188:7)"}