Add ability to set mode only with rig_set_mode by using Mode=NONE

src/rig.c

@@ -2106,6 +2106,11 @@ int HAMLIB_API rig_set_mode(RIG *rig, vfo_t vfo, rmode_t mode, pbwidth_t width)
     }
 
     if (vfo == RIG_VFO_CURR) { vfo = rig->state.current_vfo; }
+    else if (mode == RIG_MODE_NONE) // the we just use the current mode to set width
+    {
+        pbwidth_t twidth;
+        rig_get_mode(rig, vfo, &mode, &twidth);
+    }
 
     vfo = vfo_fixup(rig, vfo, rig->state.cache.split);