fetch: Reset remote refs list each time fetch_main is called

This prevents the fetch of the heads again in the second call of fetch_main.

Signed-off-by: Santi Béjar <sbejar@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/git-fetch.sh b/git-fetch.sh
index bcc67ab..f1522bd 100755
--- a/git-fetch.sh
+++ b/git-fetch.sh
@@ -257,6 +257,7 @@
 fetch_main () {
   reflist="$1"
   refs=
+  rref=
 
   for ref in $reflist
   do