improved code smell

[EzxD]

Reason for the change
Code smell is important for better readability

Description
I replaced stuff which can be expressed with isEmpty(). And a try with resource for closing the socket if exception gets thrown

Code examples
I replaced raw.size() == 0 with raw.isEmpty()
more important is the try with resource of the socket.
old code:

            SSLSocket sslSocket = (SSLSocket) sslContext.getSocketFactory().createSocket(
                        socket,
                        socket.getInetAddress().getHostAddress(),
                        socket.getPort(),
                        true);

                    // replace input/output streams
                    inputStream = new DataInputStream(sslSocket.getInputStream());
                    outputStream = sslSocket.getOutputStream();

                    // execute SSL handshake
                    sslSocket.startHandshake();

new code:

   try (
                      SSLSocket sslSocket = (SSLSocket) sslContext.getSocketFactory()
                        .createSocket(
                          socket,
                          socket.getInetAddress().getHostAddress(),
                          socket.getPort(),
                          true
                        )
                    ) {

                        // replace input/output streams
                        inputStream = new DataInputStream(sslSocket.getInputStream());
                        outputStream = sslSocket.getOutputStream();

                        // execute SSL handshake
                        sslSocket.startHandshake();
                    }

Checklist

• [x ] I have read and agreed to the RethinkDB Contributor License Agreement

References
Anything else related to the change e.g. documentations, RFCs, etc.

[srh]

It seems the existing code just creates an SSLSocket and then lets it get GC'd without closing it, assigning inputStream and outputStream instead. I guess the underlying socket does get closed later.

Right now I think we don't want this try block which closes the sslSocket at the end of the block. Why would we close() the sslSocket after constructing streams from it? Wouldn't those streams stop working?

I think we'd want sslSocket to be assigned to a member variable such that its lifetime is held alive as long as the streams exist.

I'll need to investigate what's going on a little bit further before merging this PR. So right now I'm leaving this open.