Documentation: quote double-dash for AsciiDoc

diff --git a/RelNotes b/RelNotes
index 8cf972cf485bbc26c479a6ac07f3005b1d188c84..0e5a85a5497d01842394a379cf6cf69908d7f9ba 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.7.0.2.txt
\ No newline at end of file
+Documentation/RelNotes/1.7.4.5.txt
\ No newline at end of file