Added faster logic for decodehtml to handle the special case

where the string being decoded doesn't have any ampersands
in it (e.g., because it's the value for an 'include virtual=...')


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@92284 13f79535-47bb-0310-9956-ffa450edef68