peer_connection_server: fix static analysis issues

coverity flags two issues on this:
* no copy constructor (and assignment operator) for things that free in the destructor
* missing return value check on setsockopt

BUG=None

Change-Id: I0671bf5f9bc0ede968f80c3686bf7bbd8eb63e98
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226743
Commit-Queue: Tommi <tommi@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34547}

examples/peerconnection/server/data_socket.h

@@ -37,6 +37,8 @@ class SocketBase {
  public:
   SocketBase() : socket_(INVALID_SOCKET) {}
   explicit SocketBase(NativeSocket socket) : socket_(socket) {}
+  SocketBase(SocketBase& other) = delete;
+  SocketBase& operator=(const SocketBase& other) = delete;
   ~SocketBase() { Close(); }
 
   NativeSocket socket() const { return socket_; }