message: Prepare changelog for v1.0.2-rc.4
diff: +Changes in [1.0.2-rc.4](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v1.0.2-rc.4) (2019-03-05)
  +=============================================================================================================
  +[Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v1.0.2-rc.3...v1.0.2-rc.4)
  +
  + * Patch users not existing when opening settings
  + [\#2752](https://github.com/matrix-org/matrix-react-sdk/pull/2752)
  + * Fix media device selectors not updating
  + [\#2751](https://github.com/matrix-org/matrix-react-sdk/pull/2751)
  + * Support linking to hosting providers
  + [\#2750](https://github.com/matrix-org/matrix-react-sdk/pull/2750)
  +
  Changes in [1.0.2-rc.3](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v1.0.2-rc.3) (2019-03-01)
  =============================================================================================================
  [Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v1.0.2-rc.2...v1.0.2-rc.3)
  