setup_pager: set GIT_PAGER_IN_USE

diff --git a/RelNotes b/RelNotes
index 59e7391e0fe0bb617e0b72887f63e6dd4813c720..5a33236ce993853babae09bf228c9cd33b0ac808 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.5.1.1.txt
\ No newline at end of file
+Documentation/RelNotes/1.7.6.1.txt
\ No newline at end of file