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

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10310 a83610d8-ad2a-0410-a6ab-fc0612d85776
back ported DHT assert fix from RC_1_0

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10311 a83610d8-ad2a-0410-a6ab-fc0612d85776
merge fixes from RC_1_0

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10312 a83610d8-ad2a-0410-a6ab-fc0612d85776