Fix typo in case that should never happen

git-svn-id: svn://svn.code.sf.net/p/fuego/code/trunk@1895 2e953b5c-c64d-0410-be54-f773e93e544c
Extract GoBoardHistory::SequenceToCurrent from GoUctPlayer::FindInitTree

git-svn-id: svn://svn.code.sf.net/p/fuego/code/trunk@1896 2e953b5c-c64d-0410-be54-f773e93e544c
Extract function SgUctTreeUtil::FindMatchingNode from SgUctTreeUtil::ExtractSubtree

git-svn-id: svn://svn.code.sf.net/p/fuego/code/trunk@1897 2e953b5c-c64d-0410-be54-f773e93e544c