gitweb: Fix file links in "grep" search

diff --git a/RelNotes b/RelNotes
index 692968f1702044f0474228f2c19f6086568ec9e4..d30cd7e62f7164978833e9ac148e3c041e996681 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.6.6.2.txt
\ No newline at end of file
+Documentation/RelNotes/1.7.8.2.txt
\ No newline at end of file