<!-- You can remove this first section if you have contributed before -->
### First time contributor checklist
<!-- replace the empty checkboxes [ ] below with checked ones [x] accordingly -->
- [ ] I have read the [README](https://github.com/WhisperSystems/Signal-Desktop/blob/master/README.md) and [Contributor Guidelines](https://github.com/WhisperSystems/Signal-Desktop/blob/master/CONTRIBUTING.md)
- [ ] I have signed the [Contributor Licence Agreement](https://whispersystems.org/cla/)

### Contributor checklist
<!-- replace the empty checkboxes [ ] below with checked ones [x] accordingly -->
- [ ] My contribution is fully baked and ready to be merged as is
- [ ] My changes are rebased on the latest master branch
- [ ] My commits are in nice logical chunks
- [ ] I have followed the [best practices](http://chris.beams.io/posts/git-commit/) in my commit messages
- [ ] I have made the choice whether I want the [BitHub reward](https://github.com/WhisperSystems/Signal-Android/wiki/BitHub-Rewards) or not by omitting or adding the word `FREEBIE` in my Git commit messages
- [ ] I have tested my contribution on these platforms:
 * GNU Hurd 1.0, Chrom{e,ium} X.Y.Z
 * Amiga OS 3.1, Chrom{e,ium} Z.Y
- [ ] My changes pass all the [local tests](https://github.com/WhisperSystems/Signal-Desktop/blob/master/CONTRIBUTING.md#tests) 100%
- [ ] I have considered whether my changes need additional [tests](https://github.com/WhisperSystems/Signal-Desktop/blob/master/CONTRIBUTING.md#tests), and in the case they do, I have written them

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### Description
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