[mod_redirect,mod_rewrite] fix segfault w/ invalid syntax (fixes #2892)
[mod_redirect,mod_rewrite] fix segfault w/ invalid syntax (fixes #2892)

(thx nti)

x-ref:
  "Segmentation fault with invalid lighttpd.conf syntax"
  https://redmine.lighttpd.net/issues/2892

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