the 2nd parm to strstr() doesn't lose const-ness, unlike the 1st parm;

thus, AP_DEBUG flavor of strstr() should declare 2nd parm as const char *,
not char *;

this eliminates a warning in mod_ssl-land


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90235 13f79535-47bb-0310-9956-ffa450edef68