Merge branch 'stable' into develop

Changelog.md

@@ -140,6 +140,7 @@ Contributions are very welcome, the hard work is done!
 
 ## Refactor
 * Sort tag autocompletion by tag name [#6734](https://github.com/diaspora/diaspora/pull/6734)
+* Make account deletions faster by adding an index [#6771](https://github.com/diaspora/diaspora/pull/6771)
 
 ## Bug fixes
 * Fix empty name field when editing aspect names [#6706](https://github.com/diaspora/diaspora/pull/6706)