Re-enable rig_flush due to command stacking occurring on K3 (and probably others)

https://github.com/Hamlib/Hamlib/issues/728

src/misc.c

@@ -1904,7 +1904,8 @@ int HAMLIB_API parse_hoststr(char *hoststr, char host[256], char port[6])
     return -1;
 }
 
-#define RIG_FLUSH_REMOVE
+//K3 was showing stacked command replies so re-enabling this
+//#define RIG_FLUSH_REMOVE
 int HAMLIB_API rig_flush(hamlib_port_t *port)
 {
 #ifndef RIG_FLUSH_REMOVE