isascii isn't universal, alas..

Submitted by:	gil <pg@sweng.stortek.com>
Reviewed by:	Martin Kraemer, Ken Coar


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@84274 13f79535-47bb-0310-9956-ffa450edef68