Add another bug fix to the release notes

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

Author: dscho

installer/ReleaseNotes.md

@@ -42,6 +42,7 @@ This package contains software from a number of other projects including Bash, z
 * The text in the installer describing the terminal emulator options [is no longer cut off](https://github.com/git-for-windows/build-extra/pull/69).
 * The `connect.exe` tool to allow SSH connections via HTTP/HTTPS/SOCKS proxies [is included in Git for Windows again](https://github.com/git-for-windows/build-extra/pull/73), as it was in Git for Windows 1.x.
 * The `LANG` variable is [no longer left unset](https://github.com/git-for-windows/git/issues/298) (which caused troubles with vim).
+* `call start-ssh-agent` [no longer spits out bogus lines](https://github.com/git-for-windows/git/issues/314).
 
 ##Changes since Git-2.4.6 (July 18th 2015)