Fix another bug that Ben's const char * changes identified... this fix is

untested though.  It's not correct to modify the return from ap_table_get
under any circumstance, even if you are about to delete it from the
table.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@81594 13f79535-47bb-0310-9956-ffa450edef68