rosbridge_suite: 0.6.4-0 in 'indigo/distribution.yaml' [bloom]

Increasing version of package(s) in repository `rosbridge_suite` to `0.6.4-0`:

- upstream repository: https://github.com/RobotWebTools/rosbridge_suite
- release repository: https://github.com/RobotWebTools-release/rosbridge_suite-release.git
- distro file: `indigo/distribution.yaml`
- bloom version: `0.5.12`
- previous version for package: `0.6.3-0`

## rosapi

- No changes

## rosbridge_library

- No changes

## rosbridge_server

```
* add backports to setup.py, so backports.ssl_match_hostname can be properly resolved
* Contributors: Nils Berg
```

## rosbridge_suite

- No changes