Try another fix for MacOS compile

https://github.com/Hamlib/Hamlib/issues/1256

rigs/yaesu/newcat.c

@@ -10852,7 +10852,7 @@ int newcat_set_cmd_validate(RIG *rig)
             case RIG_MODEL_FT991:
             case RIG_MODEL_FTDX101MP:
             case RIG_MODEL_FTDX3000:
-                strcpy(valcmd, "");
+                strcpy(valcmd, ";");
                 break;
             // these models do not work with a single ;
             case RIG_MODEL_FT897: