Buffered read data on SSL socket might not immediately get read after handshake is complete

[riza]

Scenario:

1. Client SSL socket will send data immediately to the server after it is connected.
2. On the server side, the data sent will be buffered. At this point, the handshake on the server side is not yet completed. When the handshake is complete, the buffered data will not be read immediately. It will not be read unless the client proceed to send data. If this is not the case, the client will likely get a time out to the send operation.

This patch will enable reading the buffered data, immediately after the handshake is complete.

[riza]

In 5975:

Close #2193: Buffered read data on SSL socket might not immediately get read after handshake is complete.