mod_lua: Use binary strstr for finding endpoints of a multipart object. (How...

mod_lua: Use binary strstr for finding endpoints of a multipart object. (How did this EVER work?! *sigh*)

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1588761 13f79535-47bb-0310-9956-ffa450edef68