Enable async by default -- this prevents WSJT-X from crashing when transceive mode is on for the IC9700

https://github.com/Hamlib/Hamlib/issues/1264

NEWS

@@ -31,6 +31,7 @@ Version 4.6
         * Fix FTDX3000 rig split
 
 Version 4.5.5
+        * Enable async mode by default to prevent WSJT-X crash on IC9700 with transceive on
         * Fix IC7610 get_powerstat to disable it -- cannot read power status
         * Fix K3 K22 command error for remote operations
         * Fix Gemini DX1200 gemini_set_level

src/rig.c

@@ -560,7 +560,7 @@ RIG *HAMLIB_API rig_init(rig_model_t rig_model)
 #endif
 
     rs->priv = NULL;
-    rs->async_data_enabled = 0;
+    rs->async_data_enabled = 1;
     rs->rigport.fd = -1;
     rs->pttport.fd = -1;
     rs->comm_state = 0;