アクセス多すぎて、DB接続数が増えすぎたのが原因の模様。

```
User: CONNECT FAILED: [mdb2_error: message="MDB2 Error: unknown error" code=-1 mode=return level=notice prefix="" info="_doConnect: [Error message: User 'senooken_gnusocialjp' has exceeded the 'max_user_connections' resource (current value: 5)]
```