apply Steven Siloti's patch to client_test to enable fixed slots choker when specifying the number of unchoke slots

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@10561 a83610d8-ad2a-0410-a6ab-fc0612d85776
merged changes from RC_1_0

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@10566 a83610d8-ad2a-0410-a6ab-fc0612d85776
merged changes from RC_1_0

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@10568 a83610d8-ad2a-0410-a6ab-fc0612d85776