git-fetch: fix --keep vs --thin

When --keep is specified there is no reason to pass --thin to git-fetch-pack,
which are mutually exclusive.  This does not hurt because fetch-pack disables
thin transfer when both are given internally, but still is confusing.

Signed-off-by: Junio C Hamano <junkio@cox.net>

git-fetch.sh

@@ -20,6 +20,7 @@ verbose=
 update_head_ok=
 exec=
 upload_pack=
+keep=--thin
 while case "$#" in 0) break ;; esac
 do
 	case "$1" in
@@ -347,7 +348,7 @@ fetch_main () {
     ( : subshell because we muck with IFS
       IFS=" 	$LF"
       (
-	  git-fetch-pack $exec $keep --thin "$remote" $rref || echo failed "$remote"
+	  git-fetch-pack $exec $keep "$remote" $rref || echo failed "$remote"
       ) |
       while read sha1 remote_name
       do