SslHander wrap conditional direct buffer allocation

Motivation:
The SslHandler currently forces a direct buffer is used as the input to the SSLEngine.wrap(..) operation. This allocation may not always be desired and should be conditionally done.

Modifications:
- Use the pre-exsiting  variable as the condition to do the conversion.

Result:
- An allocation of a direct byte buffer and a copy of data is now not required for every SslHandler wrap operation.