lighttpd: bump to version 1.4.32

One important denial of service (in 1.4.31) fix: CVE-2012-5533[1].

NOTE: There are some errors about missing commands during the build, but
I'm pretty sure they were there before. And the result seems to be
working anyway...

 * /usr/bin/file: No such file or directory
 * /bin/sh: line 2: which: command not found
 * /tmp/nix-build-lighttpd-1.4.32.drv-0/lighttpd-1.4.32/libtool: line 1085: ldconfig: command not found

[1] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-5533