Object key iteration skips first matching key and repeats the last key twice (Adobe XD)
**Which version of the plugin are you using?**
[ ] Data Populator for Sketch
[x ] Data Populator for Adobe XD

**Describe the bug**
The Data Populator plugin will skip the first "id" key, and start at the second "id" key. Then when it gets to 8th "id" key, it will repeat it twice.

**To Reproduce**
Steps to reproduce the behavior:

1. Create 8 text layers and put the placeholder text {id} in all of the layers.
2. Make sure the layer names have removed the curly braces from the layer name.
3. Select all the layers on the artboard.
4. Go to the Menu and choose Plugins > Data Populator > Populate with preset 
5. Use the built in Data Populator preset .json file called "demo/boardingpass.json"
6. Uncheck the setting that says, "Randomize data order"
7. Run the Data Populator plugin on 8 text layers.

**Expected behavior**
I expect 8 text layers in numerical order from 1 to 8.

**Screenshots**
<img width="333" alt="image" src="https://user-images.githubusercontent.com/514812/55901958-72c23e80-5b98-11e9-9570-b5350e8a0957.png">

**Environment (please complete the following information):**
 - macOS Version: MacOS Mojave 10.14.4
 - Adobe XD Version Adobe XD 18.0.12.9
 - Plugin Version 1.1.4