Update README.md

Author: Stephan Dilly

README.md

@@ -77,7 +77,6 @@ These are the high level goals before calling out `1.0`:
 * file history log ([#381](https://github.com/extrawurst/gitui/issues/381))
 * visualize branching structure in log tab ([#81](https://github.com/extrawurst/gitui/issues/81))
 * notify-based change detection ([#1](https://github.com/extrawurst/gitui/issues/1))
-* support rebase branch ([#816](https://github.com/extrawurst/gitui/issues/816))
 * interactive rebase ([#32](https://github.com/extrawurst/gitui/issues/32))
 * popup history and back button ([#846](https://github.com/extrawurst/gitui/issues/846))