make git a bit less cryptic on fetch errors

The remote server might not want to tell why it doesn't like us for
security reasons, but let's make the client report such error in a bit
less confusing way.  The remote failure remains a mystery, but the local
message might be a bit less so.

[jc: with a gentle wording updates from Andy Parkins]

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

git-fetch.sh

@@ -96,7 +96,7 @@ fi
 
 # Global that is reused later
 ls_remote_result=$(git ls-remote $upload_pack "$remote") ||
-	die "Cannot find the reflist at $remote"
+	die "Cannot get the repository state from $remote"
 
 append_fetch_head () {
     head_="$1"