Description
Feature 'Apply new properties basing on' does not work for property 'Event text renderer properties'. An empty field is set.

Reproduce

1. Created datasource as ds_1(virtual, enabled) and datapoint dp_1(binary, no change, enabled);
2. Open 'Datapoint properties' for dp_1 (Edit ds_1 -> Click on 'Datapoint properties' for dp_1 ;
3. In section 'Event text renderer properties' and property 'Type' set 'Binary';
4. Set "_zero" in Zero property, and "_one" in One property;
5. Click on 'Save', if ok then visible 'Data point has been saved';
6. Created dp_2 (binary, no change, enabled) in ds_1;
7. Open 'Datapoint properties' for dp_2 (Edit ds_1 -> Click on 'Datapoint properties' for dp_2;
8. In section 'Apply new properties basing on' and property 'Select point' select dp_1;
9. Click on 'Apply' and 'Accept' in popup 'Apply new properties';
10. In section 'Event text renderer properties' empty field -> error;

Spec:

• Version 2.6.15

Additional context