message: Prepare changelog for v0.8.7-rc.4
diff: +Changes in [0.8.7-rc.4](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v0.8.7-rc.4) (2017-04-11)
  +=============================================================================================================
  +[Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v0.8.7-rc.3...v0.8.7-rc.4)
  +
  + * Fix people section vanishing on 'clear cache'
  + [\#799](https://github.com/matrix-org/matrix-react-sdk/pull/799)
  + * Make the clear cache button work on desktop
  + [\#798](https://github.com/matrix-org/matrix-react-sdk/pull/798)
  +
  Changes in [0.8.7-rc.3](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v0.8.7-rc.3) (2017-04-10)
  =============================================================================================================
  [Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v0.8.7-rc.2...v0.8.7-rc.3)
  