Update SSLSocketChannel2.java

[sahnjeok]

Description

'handshakeStartTime' global long variable is added and isHandShakeComplete() function is updated.
In isHandShakeComplete function, if wss handshake is not completed in 10s, close this channel to prevent cpu overload or unexpected channel error.

Related Issue

Fixes #896

Motivation and Context

When WSS port is opened, if new client is connected and no ssl packet is received from client, high cpu load happens.

How Has This Been Tested?

1. open wss port
2. telnet to wss port and wait
3. high cpu load happens

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.