t5520: test --rebase failure on unborn branch with index

diff --git a/RelNotes b/RelNotes
index 1b089b9c19f48362df4ac6c6cb16638a5d6d898a..c5fa3efb98246d99bdf736237b7cf759f01a1657 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/1.9.5.txt
\ No newline at end of file
+Documentation/RelNotes/2.2.2.txt
\ No newline at end of file