When drain() is called, return immediately if we're already performing a callback to tell ProxyClient why we'd like to disappear.
When drain() is called, return immediately if we're already performing a
callback to tell ProxyClient why we'd like to disappear.


git-svn-id: 9e2532540f1574e817ce42f20b9d0fb64899e451@19 4068ffdb-0463-0410-8185-8cc71e3bd399

splbio/wanproxy,splbio/wanproxy,splbio/wanproxy,diegows/wanproxy,diegows/wanproxy,diegows/wanproxy