Start arana server, execute TestSelect method in integration_test.go will case panic.

[dongzl]

Start arana server, execute TestSelect method in integration_test.go will case panic.

[Lvnszn]

When I start arana firset then start mysql container. Then reproduce it.

• start arana with cmd.
• docker-compose up -d mysql
• testSelect

The console of server show as below

The console of test show as below

[dk-lockdown]

need ComQuit command, before connection close.

[Lvnszn]

@dongzl
这个 recycleRead，之前一定有个readEphemeralPacketDirect，这个方法，这两个是成对出现的，readEphemeralPacketDirect 将currentEphemeralPolicy 设置为 ephemeralRead，recycelRead 将 currentEphemeralPolicy 设置为 ephemeralUnused，前提是 currentEphemeralPolicy = ephemeralRead，否则报错。

重点检查这两个方法是不是成对出现，是否有地方调用了 recycleRead，而没有在之前调用 readEphemeralPacketDirect

[dongzl]

Fixes by #79 .