mv: let 'git mv file no-such-dir/' error out

diff --git a/RelNotes b/RelNotes
index 8fbe7db0e2a61ae4952f611b02d5a61bbcaf2b77..0064299c0e0cbe3e133d4464f2ab65d89324a0ab 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.5.4.7.txt
\ No newline at end of file
+Documentation/RelNotes/1.8.5.1.txt
\ No newline at end of file