Mention New Feature in release notes

The desired HTTP version (HTTP/2 or HTTP/1.1)
[can now be configured via the `http.version`
setting](git-for-windows/git#1968).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

ReleaseNotes.md

@@ -43,6 +43,7 @@ This package contains software from a number of other projects including Bash, z
 * Comes with [Git LFS v2.6.1](https://github.com/git-lfs/git-lfs/releases/tag/v2.6.1).
 * Comes with [Bash v4.4 patchlevel 023 ](https://tiswww.case.edu/php/chet/bash/NEWS).
 * Commands to interact with CVS repositories were considered obsolete [and have been removed](https://github.com/git-for-windows/build-extra/commit/59b521a3b).
+* The desired HTTP version (HTTP/2 or HTTP/1.1) [can now be configured via the `http.version` setting](https://github.com/git-for-windows/git/pull/1968).
 
 ### Bug Fixes