Post HTTPCORE-370 minor code optimization

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/branches/4.3.x@1563154 13f79535-47bb-0310-9956-ffa450edef68
merge fix for HTTPCORE-371 to the 4.3.x branch


git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/branches/4.3.x@1563377 13f79535-47bb-0310-9956-ffa450edef68
Improved exception handling in HttpAsyncService