PBAP: Check column value isn't null when query contacts

        int indexData = c.getColumnIndex(Data.DATA1);

        int indexMimeType = c.getColumnIndex(Data.MIMETYPE);

        String contactId, data, mimeType;

        while (c.moveToNext()) {

            if (c.isNull(indexCId)) {

                Log.w(TAG, "_id column is null. Row was deleted during iteration, skipping");

                continue;

            }

            contactId = c.getString(indexCId);

            data = c.getString(indexData);

            mimeType = c.getString(indexMimeType);