fix log submission description
fix log submission description

(This moves around but does not update the text on the log auditing application.)

Paraphrase Ben Laurie's description of dynamic fetching of SCTs from https://groups.google.com/forum/#!topic/certificate-transparency/bOyMRAKR_es
trawick/ct-httpd,tomrittervg/ct-httpd,tomrittervg/ct-httpd,trawick/ct-httpd,tomrittervg/ct-httpd,trawick/ct-httpd