Document why the for-each loop is not used here

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1544988 13f79535-47bb-0310-9956-ffa450edef68
Rename local variable to avoid clash with field

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1544989 13f79535-47bb-0310-9956-ffa450edef68