osTicket/osTicket-1.7 — pull request #699 by greezybacon (2013-09-04 13:54:43+00:00)
Title: Use the correct Content-Type header for CAPTCHA

Some security inspection appliances and load balancers don't appreciate something in the HTTP headers that is not a valid HTTP header. Furthermore, the browser needs the Content-Type header to identify that the image is not the PHP default of text/html