AP_Mount: Only save converted mount if mount was previously set in th…

…e first place

The mount library force configures the mount type on conversion, even if the mount was never configured in the first place

libraries/AP_Mount/AP_Mount.cpp

@@ -1015,7 +1015,10 @@ void AP_Mount::convert_params()
     // convert MNT_TYPE to MNT1_TYPE
     int8_t mnt_type = 0;
     IGNORE_RETURN(AP_Param::get_param_by_index(this, 19, AP_PARAM_INT8, &mnt_type));
-    if (mnt_type > 0) {
+    if (mnt_type == 0) {
+        // if the mount was not previously set, no need to perform the upgrade logic
+        return;
+    } else if (mnt_type > 0) {
         int8_t stab_roll = 0;
         int8_t stab_pitch = 0;
         IGNORE_RETURN(AP_Param::get_param_by_index(this, 4, AP_PARAM_INT8, &stab_roll));
@@ -1025,8 +1028,9 @@ void AP_Mount::convert_params()
             // conversion is still done even if HAL_MOUNT_SERVO_ENABLED is false
             mnt_type = 7;  // (int8_t)Type::BrushlessPWM;
         }
+        // if the mount was previously set, then we need to save the upgraded mount type
+        _params[0].type.set_and_save(mnt_type);
     }
-    _params[0].type.set_and_save(mnt_type);
 
     // convert MNT_JSTICK_SPD to MNT1_RC_RATE
     int8_t jstick_spd = 0;