fix assert in the dht when relaxing the routing table IP restriction

git-svn-id: http://libtorrent.googlecode.com/svn@10310 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
back ported DHT assert fix from RC_1_0

git-svn-id: http://libtorrent.googlecode.com/svn@10311 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
merge fixes from RC_1_0

git-svn-id: http://libtorrent.googlecode.com/svn@10312 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda