fixed iterator bug introduced when merging the udp trackers over to use the main udp socket
fixed iterator bug introduced when merging the udp trackers over to use the main udp socket

git-svn-id: c39a6fcb73c71bf990fd9353909696546eb40440@4669 a83610d8-ad2a-0410-a6ab-fc0612d85776

mirror/libtorrent,mirror/libtorrent,john-peterson/libtorrent-old,john-peterson/libtorrent-old,john-peterson/libtorrent-old,mirror/libtorrent,john-peterson/libtorrent-old,mirror/libtorrent,mirror/libtorrent,john-peterson/libtorrent-old,john-peterson/libtorrent-old,mirror/libtorrent