BgReading.copyFrom: don't update local data.

Like the 'valid' flag, which is not copied and is not synced with
NS, don't sync sourcePlugin or isFiltered.
Otherwise there might be a race condition if the NS-roundtrip of a
locally received BG updates the sourcePlugin field to null,
thus leaving no values for the loop to loop with.

app/src/main/java/info/nightscout/androidaps/db/BgReading.java

@@ -152,8 +152,6 @@ public class BgReading implements DataPointWithLabelInterface {
         raw = other.raw;
         direction = other.direction;
         _id = other._id;
-        sourcePlugin = other.sourcePlugin;
-        isFiltered = other.isFiltered;
     }
 
     // ------------------ DataPointWithLabelInterface ------------------