* Fix a off-by-one error in parse_format_tag in the case that the last character

  of the string to which *sa points is a %. In this case the while loop in
  parse_format_string would call parse_format_tag with a pointer to a memory
  region that starts one byte after the string to which s in parse_format_string
  points to.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@499567 13f79535-47bb-0310-9956-ffa450edef68