Fix nasa#969, socket accept using incorrect record

The OS_SocketAccept call was using the incorrect token, using
the server/acceptor socket when it should have used the connection
socket.

The bug overwrote data in the acceptor socket, but it would only cause
an issue when the user attempted to use the server socket to accept
a second connection, but the tests only performed a single connection.

This also improves the network-api-test to do multiple connections,
re-using the same acceptor socket between them.

src/os/shared/src/osapi-sockets.c

@@ -266,7 +266,7 @@ int32 OS_SocketAccept(osal_id_t sock_id, osal_id_t *connsock_id, OS_SockAddr_t *
             if (return_code == OS_SUCCESS)
             {
                 conn_record = OS_OBJECT_TABLE_GET(OS_global_stream_table, conn_token);
-                conn        = OS_OBJECT_TABLE_GET(OS_stream_table, sock_token);
+                conn        = OS_OBJECT_TABLE_GET(OS_stream_table, conn_token);
 
                 /* Incr the refcount to record the fact that an operation is pending on this */
                 memset(conn, 0, sizeof(OS_stream_internal_record_t));