[mod_fastcgi] fix memleak with FastCGI auth,resp (fixes #2894)
[mod_fastcgi] fix memleak with FastCGI auth,resp (fixes #2894)

fix memleak in mod_fastcgi when FastCGI is used for both authentication
and response on the same request

(thx rschmid)

x-ref:
  "Memory leak if two fcgi calls with one request (authentication and response)"
  https://redmine.lighttpd.net/issues/2894

lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4