Improve the fix for https://issues.apache.org/bugzilla/show_bug.cgi?id=44312
Check that addWrapper/removeWrapper, add/clear/removeWelcomeFile[s] are performed on the real Host, as expected by the caller.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1608824 13f79535-47bb-0310-9956-ffa450edef68