Fix hamlib_port_t_deprecated backwards compatiblity

https://github.com/Hamlib/Hamlib/issues/894

include/hamlib/rig.h

@@ -2166,6 +2166,10 @@ typedef struct hamlib_async_pipe hamlib_async_pipe_t;
  * Of course, looks like OO painstakingly programmed in C, sigh.
  */
 //! @cond Doxygen_Suppress
+// DO NOT CHANGE THIS STRUCTURE ALL UNTIL 5.0
+// Right now it is static inside rig structure
+// 5.0 will change it to a pointer which can then be added to
+// At that point only add to the end of the stucture
 typedef struct hamlib_port {
     union {
         rig_port_t rig;     /*!< Communication port type */
@@ -2238,6 +2242,8 @@ typedef struct hamlib_port {
 } hamlib_port_t;
 
  
+// DO NOT CHANGE THIS STRUCTURE AT ALL
+// Will be removed in 5.0
 typedef struct hamlib_port_deprecated {
     union {
         rig_port_t rig;     /*!< Communication port type */
@@ -2297,17 +2303,6 @@ typedef struct hamlib_port_deprecated {
     } parm;                 /*!< Port parameter union */
     int client_port;      /*!< client socket port for tcp connection */
     RIG *rig;             /*!< our parent RIG device */
-
-    int asyncio;            /*!< enable asynchronous data handling if true -- async collides with python keyword so _async is used */
-#if defined(_WIN32)
-    hamlib_async_pipe_t *sync_data_pipe;         /*!< pipe data structure for synchronous data */
-    hamlib_async_pipe_t *sync_data_error_pipe;   /*!< pipe data structure for synchronous data error codes */
-#else
-    int fd_sync_write;          /*!< file descriptor for writing synchronous data */
-    int fd_sync_read;           /*!< file descriptor for reading synchronous data */
-    int fd_sync_error_write;    /*!< file descriptor for writing synchronous data error codes */
-    int fd_sync_error_read;     /*!< file descriptor for reading synchronous data error codes */
-#endif
 } hamlib_port_t_deprecated;
 //! @endcond